In the first part of this blog, we made the case for an objective look at three parameters that define the value of an innings in a one day international cricket. Using data, it is possible to compare the relative impact of batsmen’s innings in the context of a single game. The three parameters offered were scores, strike rates, and time of innings.
While scores and strike rates are recorded as a matter of routine, the weightage given to the stage of innings needs a bit of calibration. Let us assume a par score of 320 in 50 overs. A typical way to construct an innings like this would be to score 60 off the first 10, score at 5.5 an over for the next 30 (165 runs in 30 overs) and score 95 off the final 10 overs. If a batsman has a strike rate of more than a run-a-ball in the first 10, that innings is given a higher weightage. If a batsman continues to score at a run-a-ball in the final 10, the weightage of this innings in lower.
The following are three illustrations of the proposed method of rating a batting innings:
- An opening batsman scores a run-a-ball 80 playing in the first 20 overs.
- A batsman coming into bat in the 15th over at the fall of the 2nd wicket and gets 50 in 60 balls.
- A batsman coming into bat in the 42nd over at the fall of the 5th wicket and scores 45 in 35 balls.
Illustration 1:
- The par strike rate during the first 20 overs would be 96. A run-a-ball 80 in the first 20 overs is marginally better than par so this will be given a weightage factor of 1.04 The value of this innings is computed using a formula:
- Weightage factor x (Score x Strike Rate) / 100 or
- 1.04 * 80 * 100/100 = 83
- The impact would be positive +3 (adjusted value vs actual score)
- If this innings had a strike rate of 75 for instance, this would be lower than a par strike rate for that period, so the weightage factor would be adjusted to 0.78 and the value of the innings would fall to 47 and the impact would be -33
Illustration 2:
- In this case, the batsman is predominantly playing in the middle overs where the par strike rate is 92, so a strike rate of 83 is below par and the weightage adjusted to 0.9 and the value of this innings will be:
- 0.9 * 50 * 83/100 = 38
- The impact would be -12
- If this innings had a strike rate of 110 for instance, the weightage factor would be adjusted to 1.2 and the value of the innings would become 66 and the impact would be +16
Illustration 3:
- The final illustration would expect a par strike rate of 150 for that phase of the innings, so the strike rate of 128 is lower by 15% and the weightage adjusted accordingly to 0.85. The value of this innings will be:
- 0.85 * 45 * 128/100 = 49
- The impact would be +4
- If the batsman had scored 45 in 25 balls with a strike rate of 180, the weightage is adjusted to 1.2 and the value of the innings would become 97. This is a high impact innings +52
These are just theoretical computations, but the true test would be to apply this to one of the most hotly debated games of this World Cup between England v India. In the next part of the blog, we shall test this theory to tell us the real story of the high impact performances in that game.