Cricket is a batsman’s game. Whether or not that’s true, we can add another pillar to that argument: 50 over matches two days apart hit the bowlers harder than the batsman.
The last iteration of the Royal London One Day Cup took place this summer. At the time, I had a look at how fatigue impacted players, and included a stat that the “Batting Team being better rested yielded an extra 0.23 runs per over”. Re-reading that piece, it became apparent that I hadn’t shown my workings. Let’s put that right: I’ll not only demonstrate the impact, but also quantify how much is that is down to bowler vs fielder fatigue.
Step One: Demonstrate that 48 hours between matches impact performance in the field.
Taking all bowling spells from the One Day Cup, I filtered on just the bowlers who bowled more than 25 overs in the tournament and looked at how they performed in each spell relative to their tournament Economy Rate.
Bowlers (and the fielding team)
Pretty clear trend here – if a bowler played two days beforehand, their Economy rate would be 0.16+0.06 = 0.22 runs per over higher than if they had three days between games. There’s a decent sample of 863 overs for the 3 days’ rest bucket, so the data should be reliable.
There’s also some evidence that an extra day improves Economy rate even further.
No clear trend here. 0.02 runs per over is one run per match, so whatever the impact here it’s not big.
Step Two: Demonstrate the impact is partly bowler and partly fielder fatigue.
We’ll start with an assumption: spinners can bowl 10 overs repeatedly without getting tired. Admittedly, the last time I bowled 18 overs in a day I tore my groin, but for professional sportsmen I think that assumption is OK.
Now we’ll break down the 2/3/4 day rest views for bowlers by the type of bowler and see how the impact varies.
If the spinner isn’t tired, why is he going for more runs when there’s two days between games? I think it’s because his fielders are a little ragged. The odd one becomes a two, occasionally the fielder can’t quite cut the ball off.
Interpreting the table above, playing games two days apart costs 0.13 runs per over * 50 overs = 6.5 runs due to fielder fatigue plus an extra 0.21 runs for every over a fast bowler delivers.
- When should a fast bowler be rested? I’d say it’s at the point when an inferior player would be expected to perform better. I came to that conclusion after reading this piece in the Daily Telegraph about Australia’s squad rotation in the Ashes. Why were Australia only rotating their weaker bowlers? Because the best bowlers, even tired, were still better than the alternative. Hazlewood is irreplaceable.
- This analysis could be easily extended for 20-20. I’d expect a smaller effect for the shortest form of the game as each game takes half as long. Other factors to consider for 20-20 might be number of games played in the last 10 days, or the number of days travelling (a run of home games is probably less tiring than a week on the bus).
The following chart is ugly, but I just couldn’t exclude it completely – it shows that when tired, more bowlers go for a bit more than expected, and fewer go for a bit less than expected. Can’t really construct a narrative around that, though it helped persuade me that I wasn’t just inventing patterns from the data and the effect of fatigue is real.