Do BBL pitches change if the WBBL uses them first?

Earlier this week, Matthew McInerney on Twitter posted about Mark Waugh in the commentary box for a Big Bash League game (I believe the second semi-final) suggesting that WBBL matches played beforehand were producing “slow pitches” for BBL matches.

Unfortunately I didn’t see the comment, but this is something which can be analysed.

Double headers of the WBBL and BBL have been regularly scheduled throughout the last two seasons. Twenty-four out of seventy BBL games across 2015/16 and 2016/17 were scheduled immediately after WBBL matches at the same ground.

I assume that the same pitch was used for both matches in all of these double headers. So for each Big Bash League match held as part of a double header, the pitch has already been used for up to forty overs of women’s cricket that same day. At the one double header I attended, the steam roller was run over the pitch between matches, but it isn’t inconceivable that these pitches could be different.

A ‘slow pitch’ suggests to me that scores would be lower, and we can test this premise by comparing scores in matches preceded by a WBBL match, and those not preceded by such a match.

Firstly, let’s examine the total figures. My dataset doesn’t include the semi-finals and finals played in the last week, so just under 1/3 of the sample were double headers.

Double header? Matches Median runs Median balls Median run rate
Yes 21 317 235 8.18
No 45 320 234 8.35

The number of runs scored and the number of balls faced are roughly the same at the median point. The difference in the median run rate translated to 6.8 runs per match, which is slightly more than the run gap, but not much more.

Obviously this isn’t enough to answer this question. We don’t know the distribution of matches, and whether one is consistently less than another. More importantly, we don’t have a breakdown by venue. If pitches are having an impact, it seems far more plausible that there is greater difference between venues, rather than difference depending on the presence of a women’s team earlier in the day.

This first chart shows the difference between the median run rate in double headers and single matches at each of the eight grounds that hosted BBL matches in 2015/16/17.

doubleheader3.png

A larger bar indicates that run rates were higher in double headers than in other matches. What we find is that there is no difference in run rate at the Adelaide Oval and the Sydney Showground (aka Spotless Stadium) while substantially more runs were scored at double headers at the SCG and MCG. Double headers produced lower scoring rates only at Docklands, Bellerive and the WACA.

This next chart goes into a bit more detail. It shows the run rate for every match played in BBL05 and BBL06, broken down by venue. Red dots represent double headers, blue dots represent standalone matches.

doubleheader4.png

I see no clear evidence of a trend. While the highest score was at a standalone game (445 runs scored at Renegades vs Hurricanes at Docklands), there are plenty of grounds where double headers produced more runs than single matches.

The lowest performance was a standalone match at Bellerive, the Gabba, the MCG, the Sydney Showground and the WACA. Only at the SCG, Docklands and Adelaide did this honour go to a double header match.

This isn’t definitive evidence of anything, but the available data suggests to me no proof that playing a women’s match on a pitch has any impact on the scoring in the following men’s match.

Top batsmen in the W/BBL adjusted for point in the game

So yesterday I put together a blog post analysing how performance varies for batsmen based on which point in the match they come to the crease.

Today I’m going to show which players have performed the best in the Big Bash League and the Women’s Big Bash League, when their score is adjusted to reflect their opportunities.

This metric is based on this graph: how many runs does each batsman score, broken down by the over in which they entered the innings:

entry2

And here’s the same chart for women’s Twenty20 cricket:

entry6.png

The WBBL data includes the last four seasons of the state-based competition which preceded the WBBL, and it does appear that players in domestic Australian women’s Twenty20 cricket entering in the middle of the innings have performed better over the last five years. Continue reading “Top batsmen in the W/BBL adjusted for point in the game”

Win probability after the first innings

Yesterday afternoon I went to North Sydney Oval to watch the Renegades play the Strikers in the second WBBL game of the season. Yesterday’s post had pointed out that no team had won a domestic Australian women’s T20 match since 2009/10 after having been bowled out. When the Strikers were bowled out for 116, I pointed out this stat, but I was also aware that 116 was a relatively good score for a bowled-out team and likely more than most other cases of teams who lost all of their wickets.

The Strikers went on to win with relative ease after bowling out the Renegades, making it the first match in women’s domestic T20 in Australia since 2009/2010 where the team batting first lost all of their wickets and went on to win, and also the first match since at least 2009/10 where every single wicket was taken.

To help understand these chances of success, I have calculated the probability that a team batting first will win based on their score at the end of their innings. The following charts show these statistics for both men and women (although it’s worth noting the volume of data is much greater for the men).

halftimewinchanceF.png

To take the three matches played yesterday as examples:

  • The Perth Scorchers scored 119 in their first innings in the morning game. Teams scoring 116-120 won 49.4% of the time, and lost 47% of the time. Based on this, you would expect a very close contest, with Perth having roughly 50% chance of victory. We got a close result, with the Hurricanes defeating the Scorchers with an over and 5 wickets to spare.
  • The Adelaide Strikers recovered from an early collapse to score 116 after losing all of their wickets. This fell into the same category as the Scorchers innings, but the Strikers went on to win with ease after another batting collapse by the Renegades.
  • The Melbourne Stars performed strongly in the evening game, scoring 147. Women’s teams scoring 146-150 went on to win in 75% of cases, and so did the Stars – although the Thunder did well to come within six runs.

halftimewinchanceM.png

I might update these charts from time to time – at the moment they use data up to 22 November.

You can look at the data yourself here if you want to check the exact proportions, and see how many match results are included in each category.

There’s a lot more to be said about win probabilities – things get more complicated when you look at points midway through the first or second innings, at which point you also need to factor in wickets lost. I will definitely be returning to this point, but for now you can get a good sense of the likely result at the halfway point.

Is the WBBL lifting women’s T20 scores?

At the start of the first WBBL season, I wrote a blog post about women’s cricket which amongst other things analysed ‘normal’ par scores in women’s T20 cricket. I returned later to do a post specifically focusing on par scores in both men’s and women’s T20 cricket.

After writing these posts, I kept an eye on WBBL scores and thought that they were beating the par scores more often than expected, and it made me wonder whether the higher level of professionalism and the inclusion of international players was meaning that the WBBL was producing higher-scoring games. This brings us to today’s post, where I’ll run through some statistics showing how the number of runs scored per innings has changed in the WBBL, and some explanations as to why. I’ll also give some evidence that this trend is not taking place more generally.

I started with this first chart. I separated out scores based on whether the team won the match, and whether they were playing in the first innings and second innings. I had issues last season with working out how to treat winners in the second innings, as they do not necessarily have the same incentive to score as fast as possible, and we don’t know how many runs they would have scored if they had batted for the full twenty overs. The chart shows the average run rate, not the average score. Multiply by 20 to get the average score.

wt20closeness2.png

(Where a team is bowled out, I calculate their run rate as if they had batted without scoring for the remainder of their overs. Where a team ceases to play because they have won the match, I don’t do this. The data dates back to the 2009/2010 season, which is the first for which I have data for a domestic Australian women’s T20 competition.)

Interestingly, you don’t see an increase in run rates for winning sides in either innings. You see a mild increase for losing teams batting first, but the big change is for losing teams batting second.

These are the teams which are chasing down a total, and in most cases will be behind in the chase. In 2009/10, the average run rate for these teams was around 4.9 runs per over, which would total 98 runs. It almost reached 6 runs per over (120 runs) in the first WBBL season in 2015/16.

So is this is a general trend, or just one in Australia? Unfortunately I don’t have a complete dataset of women’s domestic cricket in countries like England, India or South Africa (only New Zealand has as much data as Australia), but I can compare the Australian domestic women’s game with T20 internationals and the equivalent men’s events:

wt20closeness1.png

No evidence of a similar trendline in these other datasets.

My next theory: losing teams are not being bowled out so quickly, so they last the whole innings.

wt20closeness4.png

Not true! There was a significant jump in the proportion of matches ending with the second team being bowled out in 2015/16. After slowly dropping from 2009/10 to 2014/15, last season this measure jumped from 22% to 41%. It’s also interesting to discover that not a single team that lost all ten of their wickets has gone on to win their match in the last six seasons of the WBBL and its predecessors.

I also checked out the average number of wickets lost in each innings of play:

wt20closeness3.png

The number of wickets lost per innings ticked up in 2015/16. It’s also worth noting that losing performances in the second innings have consistently lost a wicket more than losing performances in the first innings, over the last seven seasons. There’s a similar trend seen in the Big Bash League.

So losing teams, particularly those batting in the second innings, are scoring more runs relative to the teams that beat them. This is happening alongside those teams also losing more wickets (particularly in the second innings), and being much more likely to be bowled out if chasing down a target.

So if losing scores are going up, and winning scores are remaining steady, what does this mean for the closeness of games? Are they getting closer? Well, yes, they are.

wt20closeness5.png

Back in 2009-2012, the gap between the winning team and losing team was usually around 1.75-2 runs per over (35-40 runs, if the winning team bats first or wins in the final over).

This slowly declined, before crashing in 2015/16, when the gap in WBBL01 was barely one run per over.

The same isn’t true in other T20 tournaments.

wt20closeness7.png

There was an improvement in close matches in the first season of the franchise-based Big Bash League in 2011/12 but there hasn’t been a clear trend since then. There are no clear trends in close matches in T20 internationals for either men or women since 2009.

(I’ll save you yet another chart, but there is also no such trend in New Zealand women’s cricket).

So what can we learn from these stats? I have two main theories which are backed up by this data.

Firstly, the move to franchises in the WBBL last season improved competitiveness in the tournament. The NSW Breakers have been traditionally dominant in state-based women’s cricket. They’ve won all but three seasons of the National Women’s Cricket League (50-over cricket) in its 21-season history. NSW had also made the final in five out of six seasons of the state-based T20 competition which preceded the WBBL. This would explain why we see a particular increase in competitiveness in 2015/16. The old state sides had much more of an uneven pool of potential players, and the ability for players from the bigger states to move to smaller states for more opportunities would have been much less for women due to the minimal pay.

But I don’t think that explains everything – since competitiveness has been improving prior to the last season. In future posts I might try to explore this question further.

 

W/BBL live blog – Saturday 19 December

10:43pm – That’s it for tonight. I’ll return tomorrow with sporadic coverage of the three televised Twenty20 matches (along with some coverage of the other four non-televised WBBL games). In the meantime, you can also follow me on Twitter.

10:40pm – Globally, there’s four cases of a team scoring 180 or above with a lower top score. The Dolphins in South African cricket in 2006 scored 191 with a top score of 32, in 2008 Central Districts in NZ scored 180 with a top score of 33. In 2007, Otago scored 185 with a top score of 33, and in 2008 the Deccan Chargers scored 182 with a top score of 35 in the IPL.

In 2006, the Hyderabad Hawks scored 180 with a top score of 35 – the same stats as the Heat tonight.

10:35pm – One stat I’ve been tweeting about. The Heat scored 180, which is quite a high score (22/26 first-innings scores in the range have won) but wasn’t enough. One fascinating thing about their scoring was that they used seven batsmen, all of whom made it into double figures, and none of whom scored above 35. No team has ever scored anything like 180 in Australian conditions while having that amount of balance in their side.

In 2008, NSW scored 7/159 with Steve Smith top-scoring on 33, and they lost to WA. In 2010 and 2011, Sri Lanka A and Queensland each scored 149 with a lower proportion of runs scored by their top-scoring batsman.

6:42pm – So tonight’s BBL match will start in half an hour between the Brisbane Heat and the Melbourne Renegades. The Brisbane Heat had a terrible season in 2014/15 and will be hoping to recover from that position. I’m going to be out for a few hours so will likely return in the second innings with some more analysis.

6:39pm – We’ve now seen twenty out of 56 regular-season WBBL games, and some clear trends are emerging, but these are clouded by major differences in the number of matches played by each team.

The Melbourne Stars and the Sydney Thunder have both won all of their matches, although they have only played four and three games each, and they haven’t played each other. The Stars and Thunder will play each other twice in Sydney on the final weekend of the regular season, with matches at Olympic Park on Friday 15 January and at the University of Sydney on Sunday 17 January, on either side of the SCG Sydney Derby.

The Hurricanes and the Heat have both impressed. The Hurricanes chalked up five wins before losing their sixth match today, while the Heat started out with a tough competition, losing their first two matches to the Stars before narrowly losing to the Scorchers. They have since won five in a row and could win most of their remaining matches.

The Scorchers are ranked fifth, and that seems about right. They’ve won three out of five matches, which has included defeats of the Hurricanes and Heat. They’ve only played one match against a lower-ranked team, so they’re likely to improve as their schedule gets easier.

The Strikers, Renegades and Sixers have all fallen short, with no wins after four, four and six matches respectively. The Strikers and Renegades have each had some close calls, but the Sixers have been disappointing throughout the tournament.

6:28pm – The Hobart Hurricanes were aiming for a sixth successive win, but scored a below-par 108, which was then chased down by the Perth Scorchers. The Hurricanes’ bowling started well, with Scorchers opener Ellyse Villani going for a golden duck on the first ball, but the score wasn’t enough to hold them off. The Scorchers now have won three out of their five matches.

6:24pm – The Stars easily knocked over the Sixers – chasing down the Sixers’ total of 80 in only 15.5 overs and with the loss of only three wickets. The Stars have now won all four of their matches, while the Sixers have lost all six of theirs.

6:20pm – The Heat beat the Strikers this afternoon at the Gabba, with one over to spare. Star batter Grace Harris was lost to a golden duck, but her usual partner Beth Mooney paired with Jess Jonassen, scoring 48 and 67 not out respectively, most of those runs in an 89-run partnership before Jonassen was joined by Lauren Winfield, finishing off the match. The Heat have now won five matches in a row after losing their first three. The Strikers have lost all four of their matches, despite performing strongly today.

4:11pm – The Adelaide Strikers scored 9/125 in their innings against Brisbane at the Gabba (televised on One). This was a good recovery after collapsing in the middle of their innings, losing six wickets between 11.2 overs and 16.2 overs. Teams scoring 120-130 runs in the first innings have won 55% of matches.

4:07pm – The Hobart Hurricanes scored 8/109 in their innings. The team batting first only won in 10/35 matches when scoring 105-115 runs. But they then took a Scorchers wicket on the first ball, which will improve their position.

4:06pm – The Sydney Sixers women have continued their poor form, scoring 9/80 in their innings. The Melbourne Stars are on 0/6 off 1.3 overs. In women’s T20 matches in Australia where the first team scores between 70 and 90, that team lost 18 matches, tied one match and only won one match.

4:03pm – In the two WBBL matches this morning, the Thunder defeated the Renegades with three balls to spare, and the Hobart Hurricanes held on against the Perth Scorchers, who fell short by one run. The winning scores in the two matches were 130 and 133.

11:08am – Hobart is on 5/118 off 18.4 overs – which is headed for a score which would give them about a 50% chance of winning.

10:05am – We have six Twenty20 matches being played in Sydney and Brisbane today, with the first starting right now in Blacktown.

In the WBBL, the Hurricanes and Scorchers are playing at Blacktown at 10am, then the Thunder and Renegades will be playing in Brisbane at 11am. In the afternoon, the Sixers play the Stars at Drummoyne at 2:30pm and the Scorchers play the Hurricanes at Blacktown at the same time.

The first televised WBBL game starts at 2:40pm AEDT at the Gabba, with the Brisbane Heat hosting the Adelaide Strikers. Following that match, at 7:10pm AEDT the Brisbane Heat men’s team will be hosting the Renegades at the same ground.

I’m not going to be present for the whole day but I’ll drop in every now and then with little stats updates – and if you want to follow along please comment below.

Right now the Hobart Hurricanes women are on 0/5 off 1.3 overs at Blacktown. Both teams have performed well, with Hobart winning all four of their matches and Perth winning three out of their four.

WBBL – after two weeks

We’ve now had twelve matches in the Women’s Big Bash League, with the three matches in Melbourne and Sydney on the first weekend followed up by another nine matches in Perth and Launceston last weekend.

While the Sydney Thunder have only played one match, the Brisbane Heat have played six matches, so the results between the teams are still quite lopsided. So far three teams have won all their matches, three have lost all their matches, and two have mixed results.

The winning Thunder and Stars sat out the weekend, while the losing Heat and Sixers returned and were joined by the other four teams.

In summary, this is where each team stands:

  • Stars and Thunder have impressed, but we haven’t seen them this weekend.
  • The Heat lost three close matches, and have bounced back with impressive performances which suggest they will be a team to beat. They’ll still be weighed down by those three losses.
  • The Hurricanes have won all four of their matches, putting them at the top of the table, but two of those were by the slimmest of margins.
  • The Strikers and Renegades have each lost two matches – in each case, they’ve lost one narrowly and one by a large margin.
  • The Scorchers had one easy win, one narrow win and one loss.
  • The Sixers have been disappointing, losing all four of their matches, usually by large margins.

Below the fold I’ll run through the most impressive individual performances.

Continue reading “WBBL – after two weeks”

WBBL – Grace Harris hits it out of the park

We’ve had a rush of Women’s Big Bash League games being played on Friday and yesterday in Perth and Launceston, with three more due today. I’ll return following the weekend’s play with a summary of the performances, but I wanted to focus particularly on Grace Harris’ performance in last night’s match between the Brisbane Heat and the Sydney Sixers.

In this innings, she scored the first century of the WBBL, and her first century in top-level Twenty20, before turning around and achieving her best bowling figures in Twenty20 cricket. I’ll run some comparisons to show how impressive the innings was.

Continue reading “WBBL – Grace Harris hits it out of the park”

Photos from WBBL derby – Sydney vs Thunder 6 December

I wouldn’t normally post photos, but since this game had the risk of flying below the radar I decided to take a few photos, and have posted them here.

WBBL – first round summary

WBBL – first round summary

On the weekend there were three matches in the WBBL.

The first two were both between the Melbourne Stars and the Brisbane Heat at Junction Oval in Melbourne, and the third was between the Sydney Thunder and Sydney Sixers at Howell Oval in Penrith in Western Sydney.

Both of the two Melbourne matches were reasonably close and followed a similar pattern: the Stars batted first, scoring a reasonably high total and narrowly fending off a chase from the Heat.

The Sydney Thunder easily defeated the Sydney Sixers, thanks to a steady flow of wickets and heavy-hitting.

In this post I’ll summarise the key stats from each match, below the fold.

Next weekend, there’ll be seven matches in Tasmania and Western Australia over three days. I’m unlikely to cover them in the same level of detail, but if I’m around I will do some tweeting of key stats at the @strike_rate Twitter account, so follow along.

Continue reading “WBBL – first round summary”

WBBL – the best batters and bowlers

Earlier today I wrote a post explaining four key batting metrics and three key bowling metrics which can be used to measure success in Twenty20, and then I showed these stats for each of the eight WBBL teams.

For this section, I’m going to analyse players by batting and bowling. I’m going to separate players between those who have under five innings of international play, and those who have five or more, so we can get a sense of the best players amongst the international stars, and amongst the up-and-comers.

Because this could be infinitely complex, I’m going to just look at the top five for each of these fourteen metrics (seven metrics divided between international and non-international players).

Batting – internationals

Batting average Balls per innings
Stafanie Taylor 41.45 Stafanie Taylor 27.66
Meg Lanning 36.04 Charlotte Edwards 26.98
Sophie Devine 34.47 Dane van Niekerk 26.54
Alex Blackwell 34.28 Suzie Bates 25.16
Charlotte Edwards 34.14 Meg Lanning 24.66
Strike rate Boundary runs/innings
Deandra Dottin 140.11 Meg Lanning 16.53
Stacy-Ann King 133.64 Charlotte Edwards 15.58
Meg Lanning 121.80 Sophie Devine 14.12
Sophie Devine 121.59 Stafanie Taylor 14.06
Stafanie Taylor 117.62 Elyse Villani 13.88

This shows the importance of international players in the competition. Only Lanning, Blackwell and Villani are Australian, while the captains of England, West Indies and New Zealand each appear on at least three tables. Meg Lanning’s position won’t come as a surprise to anyone who followed her batting yesterday.

It’s also interesting to note that three of the top five in strike rate are West Indian cricketers.

Continue reading “WBBL – the best batters and bowlers”