Archive for the 'Statsguru' Category

Cricinfo’s Statsguru….

December 1, 2006

Statsguru on Cricinfo.com is one of the best, if not the best stats databases available online. One of the stats in this database has always intrigued me. It is the “bowler/fielder summary” in the list of batting stats. This provides a list of bowlers that a batsman has been dismissed by, and a run average for which this happens. I used to think at first, that when it said that Batsman X averaged Y against Z bowler, it is a measure of the number of runs the batsman has made off bowler Z per dismissal by bowler Z.

Not so. It is in fact, the number of runs made by a batsman in innings when he was dismissed by a particular bowler. So it does not provide a measure of a bowler’s mastery of a batsman. Take the example of Glenn McGrath and Sachin Tendulkar. McGrath has dismissed Tendulkar 6 times in Test cricket, and Tendulkar’s average against him is 22.16. This is Tendulkar’s average in all the innings in which he has been dismissed by McGrath. If you consider all the test matches that Tendulkar and McGrath have both featured (which obviously includes all the innings in which McGrath has bowled at Tendulkar in a Test match), Tendulkar’s scores have been

11, 0, 61, 0, 116, 52, 45,
4, 76, 65, 10, 10, 126,
17, 8, 2, 5, 55

So Tendulkar’s average in innings where McGrath bowled at him is 36.8.

The point is, that the 22.16 average appears in Tendulkar’s statsguru list, not McGrath’s. 22.16 is not a measure of Tendulkar’s performance against McGrath, 36.8 is. Similarly, McGrath’s “batsmen dismissed” results should list 36.8 vs Tendulkar. If the statistic is to be a real McGrath v Tendulkar statistic, then it must list the number of runs Tendulkar has made off the bowling of Glenn McGrath (in his innings against Australia) and divide that figure with the number of times McGrath has dismissed Tendulkar. That would be the truest McGrath v Tendulkar statistic. The current statistical measure is inaccurate, assuming that the purpose of the statistic is to provide a measure of a batsman’s performance against a particular bowler. This is important because statistics invariably cause the reader to find conclusions why they do not actually support, but seem to support.

Brian Lara has a 41.40 average in 15 innings in the “bowler’s dismissed by” result against Glenn McGrath’s name. In Test Matches where both Lara and McGrath have featured, Lara’s scores are as follows:

65, 9, 88, 43, 24, 14*,
65, 0, 26, 44, 2, 1, 2,
2, 9, 78, 132, 62, 3,
213, 8, 153*, 100, 7 , 0,
4, 0, 17, 182, 39, 16, 0,
35, 28, 14, 42, 68, 60,
30, 14, 13, 45, 226, 17

Lara has made 2000 runs in 42 complete innings in Tests where McGrath has played, an average of 47.16.

Lara’s average against Australia is 52.12 over 30 Tests, Tendulkar’s is 53.11 over 18 Test matches.

McGrath v Lara should read 47.16 (52.12)
McGrath v Tendulkar should read 36.80 (53.11)

It is clear that McGrath has had more success against Tendulkar than he has had against Lara. It is also clear that his difference is not as much as 22.18 vs 41.40 suggests. What it also reveals is the disparity between the number of Test innings that Tendulkar and Lara have played against McGrath (16 for Tendulkar vs 44 for Lara).

Cricinfo needs to revise this statistic in their statsguru in my view….

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