Saturday, December 23, 2006

Fast bowlers need at least four days rest


This seems almost certain, if baseball pitchers are a reasonable comparison.

In baseball the starting pitcher usually throws (from a standing position) about 100 plus pitches before being taken-off and rested - for *four days*!

Yet a pitcher will do nothing but throw - plus catch a few balls that come in his direction, and (in the National League) try to bat.


By comparison a fast bowler probably delivers well in excess of a hundred deliveries a day, with a run-up which may be long and quick, and he is expected to field just like anyone else when not bowling (and he has to bat - and run between the wickets, of course).

Then he often comes back and does the same the next day - maybe three days out of five? - then (in back-to-back tests) he must travel (perhaps in cramped conditions, unable to stretch for long periods), and perhaps get two or three days off before starting all over.


Baseball starting pitchers are rested for four days between starts, because careful record-keeping has shown that otherwise their performance declines significantly (ie. their speed and control) and their career is probably shortened as well.

This kind of data is routinely gathered in baseball. The result is that Major League teams have at least five starters in a five day rotation.


But has anyone ever even kept such statistics for cricket? Or acted upon the results?

How do quick bowler's average performances compare on day two of a long innings compared with day one: what is the average speed, the number of wides and no-balls, the economy rate, the number of wickets and bowling average?

Does a fast bowler's performance decline (on average) in the second of back-to-back tests? Does it matter whether his team bowls or bats first in the second test?  

Do bowler's injuries correlate with number of deliveries bowled per unit time, over a sufficiently large sample of bowlers?

How much rest do bowlers need on average, to maintain their performance levels; and how frequently must they rest in order to maintain their pace and accuracy?


My hunch is that this statistical information is not routinely gathered because people are worried about what they might find, and the consequences.

On the other hand, if carefully gathered and analyzed, such statistics would allow quick bowlers to be rested such that their performance levels were maintained.

In particular we need to know at what point it would (on average) give better results to employ an inferior but fresher bowler, compared with a better one who is knackered.


There might be a huge reward for better management of bowlers, because even fast-balling baseball pitchers are sometimes able to keep playing at the highest level into their early forties (eg. currently including Roger 'the Rocket' Clemens - 44; Randy 'the Big Unit' Johnson - 43) - while quick bowlers such as Glenn McGrath are considered ancient at 35, and have-to retire from international cricket.


[Note added 6 Dec 2013 - Subsequent revelations have suggested that it may be that some of these long-lived pitchers achieved this feat partly by usage of performance-enhancing drugs. However, if so, perhaps it is reasonable to assume that such drugs were also used by the younger players, so it may not affect the point being argued.]