Sunday, 15 November 2015

Batsmen and the burden of the captaincy

It must be tough being a test match captain. The potential for days in the field, a mind full of bowling changes and fielding positions. Commentators and fans analysing your every move. Are you being too funky or not funky enough? Then, after all that, you have to go out and bat. As well as being held responsible for the collective success or failure of your team, you have your personal performance to take care of. The burden is heavy. Surely you're exhausted. Something must give, mustn't it?

It seems to be a fairly commonly held belief that the cost of doing what test teams usually do, in making one of their best batsmen the captain, will often come in the form of reduced run output from the player in question. In discussions of Joe Root, England's presumptive captain-in-waiting, I have certainly heard it raised that making him captain will dent his prolific run scoring.

It seems a reasonable enough worry to have. The captaincy certainly carries a lot of pressure with it, and a lot of extra responsibility which one would have thought would make it harder to focus on one's batting. But what does the evidence say? How does the captaincy affect a batsman's performance?

The graph below plots the batting average when playing as captain against the batting average when not playing as captain for all the test captains who have led their side at least 30 times.

Points below the blue line represent players who's batting average was lower when captaining, and points above the line represent players who were more prolific when skippering. There are two things to notice here:
1) Most points fall fairly close to the blue line- i.e. for most of the players in our sample their batting averages with or without the captaincy only differ a little bit.
2) There are more points above the line than below it (26 vs 17 to be precise)- i.e. it's more common for a player's average to improve with the captaincy than to decrease.

On average, the players in this sample increased their batting average by 3.76 runs when carrying the captaincy burden. I wouldn't read too much into that positive shift as it is much smaller than the sample standard deviation. The main take home message is that for most players the captaincy doesn't seem to make much difference to their average, and only for very few does their average significantly decrease.

I have heard it said that the England captaincy may carry peculiar pressures- perhaps due to the often slightly tempestuous relationship between players, media and fans in English sport. So one may wonder about the England captains of recent vintage in our sample. Of those only, Michael Vaughan (36.02 with captaincy vs 50.98 without) shows a big negative shift. Alastair Cook (49.94 vs 46.36), Andrew Strauss (40.76 vs 41.04) and Nasser Hussain (36.04 vs 38.10) all have pretty similar numbers for the two cases. Mike Atherton shows a slightly bigger shift but in the positive direction (40.58 vs 35.25).

So there's really not much compelling evidence to make us think that the captaincy depresses the run scoring of batsmen. But why, then, is this believed? I don't know, but my personal theory is this: when a player is given the captaincy they're usually coming off the back of a pretty good run- since you generally don't want to give the captaincy to a player unsure of their place. But all good runs must end eventually, for all players, captaincy or no. Whenever that does happen, this will be widely attributed to the pressures of captaincy catching up with them and the belief is perpetuated.

Test match captains are made of stern stuff- despite the pressure, they'll just carry on batting.

Tuesday, 10 November 2015

Pakistan's spinners have mastered the UAE where others have failed

For this post, I was reflecting on England's recent performance against Pakistan in the UAE. The consensus, after England's 2-0 defeat, seems to be that they performed fairly well but just came up against a side better suited to the conditions.

There's certainly a lot of truth in that. Despite the fact that Pakistan haven't been able to play tests in their home country in recent years their success in the UAE- where they've played in lieu of home matches- rivals some of the strongest home teams in test cricket. The graph below illustrates the 'home' record of each test match side since November 2010 (the period over which Pakistan have been laying regularly in the UAE). The 'x' axis shows the percentage of wins achieved by the 'home' side and the 'y' axis shows their net batting average - bowling average at home in that period.

By these measures Pakistan's record in the UAE is very close to England's in England- not bad considering they don't actually get to play at home.

The most obvious difference between the two sides was the performance of their respective spin bowlers. While England's batsmen floundered against the legspin of Yasir Shah; Adil Rashid, Moeen Ali and Samit Patel neither took regular wickets nor kept the runs down. I think it's fair to say that, in the main, they rightly haven't been over-harshly criticised, but I also think there's an air of disappointment surrounding the fact that the best spinners England could muster simply didn't seem to cut the mustard.

I would like to offer one point in mitigation of this- the UAE is actually quite a difficult place to be a non-Pakistani spinner. The graph below plots the bowling averages of 'home' and 'away' spin bowlers in each test match hosting nation since November 2010.

There's a (fairly weak) trend in the direction you'd expect- that in places where "home" spinners perform well, so do "away" spinners, at least relatively. But the performance of Pakistan's spinners in the UAE is far, far better than the overall performance of spinners for the touring sides they've been playing against. Pakistan's spinners average 29.65 in the UAE since November 2010, as compared with 44.69 for spinners from other test nations in the UAE. The difference between those two figures is the second highest for any of the test hosting nations. The largest difference between home and away spinners is in Australia, where baggy green spinners have been taking wickets at 41.63, as against 57.49 for touring sides.

So it seems that Pakistan's spinners have been finding a way to succeed in the UAE, where the best spin bowlers of touring sides have generally been struggling. Whether this is because of the pitches, because Pakistan's batsmen are really good at playing spin, something else, or a combination- I don't know. I do think that this to some extent sets the performance of England's spinners in some context- their collective average of 59.85, certainly remains a disappointment but there were always unlikely to be England's match winners in that series (although Rashid nearly was in the first test, but for the bad light). I also think it illustrates that there was never likely to be much tactical value in picking a third spinner for the third test, but perhaps a discussion of how to balance a bowling attack is one for another day.