An explainer on the performance ratings used to measure the best ODI bowling performances of all time
Pitch quality, batting quality, importance of the match and more are taken into consideration
Pat Cummins and Jhye Richardson took identical figures of 3 for 37 against a very strong Indian batting line-up in Ranchi in March this year • Getty Images
This is the base measure. The computations are such that a nine-wicket haul will get maximum points. Currently, the most wickets taken in an innings by one bowler is eight and we don't know how long the wait will be until a nine-wicket haul. This is unlike the "Runs scored" parameter, in which the maximum runs have already been reached and is capped at 200.
This important measure takes into account the quality of the batsmen dismissed and the score at which they was dismissed. Thus, it can be seen that dismissing a top batsman like Virat Kohli for a low score carries a lot of weight. However, it is also important to not allow the better batsmen to bat for a long time. Dismissing Kohli at, say, 76, still carries decent weight.
Unlike the batting strike-rate measure, this is a complex measure, since this combines the base economy rate and the ratio of the bowler's economy rate to the team economy rate. The base economy rate has a higher weight. The idea is that a spell of 10-0-45-1 has a lot going for it in this measure if the other team scored 350 but is very poor if the other team scored 160.
Like the bowling-accuracy measure, this also takes into account both the absolute strike rate of the bowler and the strike rate of the bowler relative to the rest of the team. This ensures that whether the batting team lost five wickets in 50 overs or ten wickets in 25 overs, the analysis is fair. In both the accuracy and strike-rate measures, what the bowler achieved in absolute terms and what he achieved in relative terms mean a lot.
This is based on the career-to-date bowling averages and economy rates. This ensures that the rating values calculated do not vary for future computations. It also allows for career swings, which are common for most bowlers.
Similar to the batting analysis, this is based on the RpW of the particular match. There is no use going into any history since the RpW values move drastically in this regard across time.
This parameter is based on the enormity of the task faced by the bowler at the beginning of the innings. For the first innings, the bowlers face reasonable challenges. Across the years, the bowling par scores have ranged from 191 to 234, and this value is used as the target. This is the score that gives the bowling team a 66.7% chance of success. For more details on this, please refer to my recent article on redefining par scores in ODIs. However, for the second innings, the targets have ranged from 36 to 482 and the measure takes into account the target ahead. Unlike batting, this cannot be a dynamic measure since there is no record of when the bowlers bowled for over half the matches.
This measure is a combination of three factors: the relative team strengths, the location and the result. In addition, very close results, such as win margins of under ten runs, are considered and the concerned bowlers get additional credit. Close results like one- or two-wicket losses are also rewarded a little bit. Ties carry more credit than no-result matches since a tie is considered to be a result.
Multiplying factor in the range of 95% to 125%. The 11 World Cup finals carry the maximum index value.
The overall weights for bowling spells with two wickets and more (14,796 in total) are given below. In view of the importance of wickets in the final ratings work, it is not possible to relax this criterion any further. The weight percentage will be distorted a lot, especially for the first two parameters.
SWQ: 8.5%
Acc: 12.5%
StRt: 4.9%
BatQ: 20.3%
PQI: 11.8%
Tgt: 12.9%
T/L/R: 15.9%
Anantha Narayanan has written for ESPNcricinfo and CastrolCricket and worked with a number of companies on their cricket performance ratings-related systems