Has the Impact Player rule tilted IPL in favor of batsmen?

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The Impact Player rule introduced in 2023 allows teams in the IPL to substitute a player in their XI with an Impact Player at certain stages of a game. Even though teams can use this to lengthen either their batting or bowling, the common belief is that teams deepen their batting with the additional player and that has been the catalyst behind the glut of runs we have been witnessing since 2023. This article tries to verify the veracity of this belief while analyzing how teams have used this rule so far.

For this analysis, I consider the matches played until the 15th of March, 2024. To begin with, matches in the IPL have indeed been high-scoring since the 2023 season as the first-innings average of 183.79 as opposed to the average of 171.12 in 2022 would tell you. I use 2022 to compare because the introduction of two new teams and the mega auction in 2022 brought about significant changes to team combinations. However, can this spike in average be chalked up to Impact Players? To answer this question, we need to find if this rule has been used primarily to lengthen the batting and if that corresponds to the increase in runs scored. To that end, we should analyze team combinations, and that requires identifying the roles of players.

Assigning roles to players

We can obtain the player roles from ESPNCricinfo, but the roles there seem to have been assigned manually based on subjective views of players’ roles in their teams. Since such subjective labeling can skew the analysis, we first need to find a way to objectively assign roles to players. Accordingly, I use the number of balls players faced and bowled on average in a T20 match in the last five years to categorize them as specialist batsmen, batting all-rounders, specialist bowlers, bowling all-rounders, all-rounders, and utility players.

All-rounderBalls faced >= median and balls bowled >= median
Batting all-rounderBalls faced >= median and balls bowled < median and balls bowled >= Q3 batsman
Specialist batsmanBalls faced >= median and balls bowled < Q3 batsman
Bowling all-rounderBalls bowled >= median and balls faced < median and balls faced >= Q3 bowler
Specialist bowlerBalls bowled >= median and balls faced < Q3 bowler
Utility playerBalls faced < median and balls bowled < median

An all-rounder faces and bowls balls more than or equal to the median. A batsman faces balls more than or equal to the median while bowling fewer balls than the median. A batting all-rounder is a batsman who bowls more than or equal to the third quartile batsman, and a specialist batsman is a batsman who is not a batting all-rounder. A bowler bowls more than or equal to the median while facing fewer balls than the median, and a bowling all-rounder is a bowler who faces balls more than or equal to the third quartile bowler. A specialist bowler is a bowler who isn’t a bowling all-rounder, whereas a utility player bowls and faces fewer balls than the median.

Are high scores due to Impact Players?

Armed with this data, we are now ready to verify if the batting depth has gone up since the advent of the Impact Player rule. Since 2023, teams have batted till number 8 or lower 47.09% of the time, a significant increase from just 25.68% in 2022. At the same time, Impact Players have also helped teams strengthen their bowling without sacrificing their batting depth as teams have played 6 batters only 3.43% of the time since 2023 in contrast to 27.7% in 2022. So, can we conclude that Impact Players have tipped the scale in the batsmen’s favor?

Even though batting depth has indeed increased, so has the bowling depth. Teams played less than 4 bowlers 25.68% of the time in 2022. However, the number has dropped down to a meager 8.25% since 2023. Besides, teams play more than 5 bowlers 52.91% of the time now compared to just 27.7% in 2022. The batting depth of an average team has now gone up to 7.45 from 6.95 in 2022. In the meantime, the average number of specialist bowlers has gone up from 4.02 in 2022 to 4.48. The batting depth has increased by 0.5 while the bowling depth has increased by 0.46, almost in equal amounts.

Even if we discount the increase in bowling depth that mitigates the issue of the 5th bowler being a weakling, and helps counter batsmen with their weak match-ups better, can we impute the high scores to the increase in batting depth? No, because the averages have risen since 2023 even across similar batting depths. When teams batted till 8 in 2022, they averaged 170.6 in the first innings. Since 2023, this average has been 182.27. Similarly, averages have gone up when teams batted till numbers 6 and 7 from 167.7 to 197 and from 174.23 to 185.75 respectively.

Analyzing the causes behind the high scores is beyond the scope of this article but the argument that Impact Players have favored batsmen does not hold much water. We should not forget that 2023 was the first season teams got to play on a home-away basis since the introduction of two new teams and that may have also played a part in the hemorrhage of runs. We also cannot rule out the possibility of high scores being a self-fulfilling prophecy as teams may have decided to take more risks with the bat to counter the widely believed possibility of other teams batting deep and scoring high.

How have teams used their Impact Players?

The argument that we cannot ascribe the high scores to Impact Players alone is also strengthened by the fact that different teams have utilized Impact Players differently. Chennai Super Kings (CSK), Delhi Capitals (DC), and Royal Challengers Bengaluru (RCB) have exploited Impact Players to lengthen their batting, whereas Mumbai Indians (MI), Rajasthan Royals (RR), Gujarat Titans (GT), Lucknow Super Giants (LSG), and Sunrisers Hyderabad (SRH) have strengthened their bowling. CSK have played 4 or fewer bowlers 22 times while DC have done it 17 times. Even though RCB have played 4 or fewer bowlers 16 times, they have used Wanindu Hasaranga, an all-rounder, primarily as a bowler, rendering their batting shallower than it seems on paper. RR have reinforced their bowling more than any other team, having played 6 bowlers 5 times, while GT and MI are the only other teams to have played 6 bowlers, once each. MI have played 5 bowlers 21 times and GT 22 times. KKR and Punjab Kings (PK), in contrast, have struck a balance between strengthening their batting and bowling, possibly aided by the presence of all-rounders like Sam Curran and Andre Russell.

It was thought that Impact Players would obviate the need for all-rounders. However, in contrast, the number of all-rounders in teams has gone up from 1.74 in 2022 to 1.81 since 2023. Teams like RCB, PK, KKR, and CSK have continued to back their all-rounders, allowing them to strengthen their batting or bowling. While CSK and RCB have used their all-rounders to bat deeper, PK and KKR have strengthened their bowling.

Creative uses of Impact Players

At the same time, while the conventional use of Impact Players has been subbing in a bowler when bowling second and a batsman when batting second, some teams have been creative. RR in particular have started with 6 batters in their XI when batting first. This allows them to sub in a batsman if they run out of batsmen or play 6 bowlers if they don’t lose wickets. They tried this first against SRH in Jaipur in 2023 and losing only 2 wickets meant that they could play a 6th bowler. However, surprisingly, instead of replacing a batsman, they replaced Ravichandran Ashwin after he had completed his quota of overs with Obed McCoy to bowl at the death.  This tactic of replacing a bowler after his strong phase is done with another bowler has been scarcely used, as KKR are the only other team to have done this when they replaced Harshit Rana with Suyash Sharma against LSG in 2023.

MI aped RR’s 6-batter ploy in the eliminator against LSG in 2023. However, when they lost their 5th wicket in the 17th over, they were forced to bring in Nehal Wadhera for Suryakumar Yadav. RR have used this strategy 4 times this season, and their batsmen’s performance has meant they could always play an extra bowler. MI’s only attempt at this this season, coincidentally against RR, didn’t work as they were forced to sub in Dewald Brevis after losing early wickets.

Teams have also used the Impact Player to get to a defendable score after losing too many wickets. SRH subbed in Rahul Tripathi when they found themselves 3 down in the 5th over against PK this season. Similarly, LSG brought in Deepak Hooda against DC when they lost their 4th wicket in the 8th over, DC used Abishek Porel at the death to lift them to 174 from 138 for 7, RCB used Saurav Chauhan against MI after losing their 6th wicket in the 17th over and PK used Ashutosh Sharma when they were 6 down for 103 against RR.

Even though it provides no tactical advantage, there have also been instances of a batsman replacing a batsman in the second innings. RR subbed in Abdul Basith for the dismissed Devdutt Padikkal in 2023 even though they could have replaced a bowler. GT, on the other hand, used this to replace Kane Willaimson in 2023 when he was injured while fielding.

To conclude, even though the popular notion is that the Impact Player rule has made teams bat deeper and, as a result, score faster, the reality is that teams have used this rule to deepen both their batting and bowling. At the same time, scores have been higher on average since 2023 even when teams have had similar batting depths as in 2022. All-rounders have also managed to stay relevant despite prophecies about their demise. The use of this rule has differed across teams with CSK, RCB, and DC using Impact Players to deepen their batting while MI, GT, LSG, SRH, and RR have gone bowling-heavy. Even though the use of this rule has been largely predictable, some teams, especially RR, have been creative with its use.