RCB's Impact Player strategy allows du Plessis and Harshal to flourish

Abdul Basith walked to the middle at Bengaluru's imposing Chinnaswamy Stadium needing to hit 10 runs off his first two balls in IPL cricket to clinch a victory for Rajasthan Royals against Royal Challengers Bangalore.

He looked around briefly to scope out his boundary options, then limbered up as Harshal Patel ran in to bowl. He shaped to power him over the leg side, lining up the stands at deep midwicket, but was foxed by Harshal's slower ball. The ball dribbled away for a single, and the game was RCB's.

This was a moment that exposed the difference in utility that these two teams had extracted from the Impact Player rule, a rule which has fundamentally altered the nature of selection in T20 cricket. IPL games can - and often do - turn in a single ball; off the penultimate one of the game, RCB's substitute got the better of Royals' and clinched the points.

Faf du Plessis is having a phenomenal IPL. Nearly halfway through the league stage, he is the Orange Cap holder, has scored five half-centuries in seven innings, and is striking at 165.30. Most top T20 batters are either destructive or dependable; this version of du Plessis falls into a rare category that are both.

This stellar run of form has come at 38, an age where most cricketers are long retired and working in coaching or broadcasting. Remarkably, du Plessis has done it despite suffering a grade-one intercostal strain, which would have ruled him out of his team's last two games in any other franchise league.

But the Impact Player rule has enabled him to play despite his injury. Against Punjab Kings on Thursday, he made 84 off 56 as a specialist batter, before he was replaced at the innings break. Back in Bengaluru on Sunday afternoon, he set up a second consecutive win against Royals with 62 off 39 before again being replaced at the interval.

RCB have twice made late decisions over du Plessis' participation as a fielder. He may be able to return to his role as captain - and boundary-rider - in their game against Kolkata Knight Riders on Wednesday, but for now he can console himself with the knowledge that he has made major contributions in games he would not otherwise have played.

During their win over Kings, du Plessis admitted his inclusion "probably wouldn't have been possible" but for the Impact rule. "I saw some of the boys were trying to do this new rule now where they bat and they don't field, so I thought I'd try it out," he joked to the host broadcaster.

The injury has clearly caused him discomfort. Thirteen overs into Sunday's game, at the second strategic time-out, du Plessis ran straight to the dugout after batting for over an hour in the afternoon sun; two balls later, he was run out, the first time in three IPL seasons he has been dismissed by that method.

Harshal, his replacement on Sunday, provided further evidence of RCB maximising the new rule. He suffered an injury while fielding during their victory over Kings; like du Plessis, he might well have missed the game but for the Impact Player rule allowing him to feature in one innings only.

He arrived at the Chinnaswamy with the little finger on his left hand heavily strapped, limiting his ability to grip the bat; he later suggested that he hopes it will heal "in a week or two". As a result, he was used exclusively as a bowler, replacing du Plessis at the innings break and bowling his four overs in the run chase.

After a slow start to the IPL, Harshal put in his best performance of the season, taking three vital wickets as Royals fell just short in their run chase: Yashasvi Jaiswal, mistiming a full toss to long-on; Sanju Samson, fencing an effort ball to short third; and R Ashwin, dragging a slower ball to deep midwicket after giving RCB a scare.

"The way we've been able to use Faf as a batter and myself as a bowler in this game has been really good for us," Harshal said. "Both of us are carrying injuries which don't allow us to execute one of our skills: for him, it's fielding; for me, it's batting. The Impact [Player] rule allows us to just go out and take care of our primary skills."

RCB were even able to find another loophole which they happily exploited. When Harshal briefly went off the field at the start of the fourth over, after fielding a ball at deep third, the fact that du Plessis was off the field enabled them to use an overseas player - Finn Allen - as a fielding substitute for two overs, since they otherwise only had three overseas players on the field.

But while most teams have used the rule in a similar fashion to one another this season - effectively picking a 12-man team, and replacing a specialist batter with a specialist bowler - Royals have differed, as their captain Samson suggested at the toss. "We're starting with the same XI [either way]," he said. "We might add, or we might not add."

Royals have generally selected the same balance regardless of whether they have batted or bowled first this year, featuring six batters and five frontline bowlers. They have often delayed a decision on their substitution until midway through the second innings; some calls have worked well - bringing on Adam Zampa at Chepauk, for example - but others have not.

Sunday's game appeared to expose the issues with their method. In limiting themselves to five bowling options, Royals did not have much flexibility with the ball, with no choice but to use Sandeep Sharma at the death despite his off-day. And in the absence of Riyan Parag, who did not travel to Bengaluru, they found themselves bringing in an IPL debutant at No. 8 - leaving Jason Holder unused with the bat for the fourth time in his six appearances this season.

Royals' results this season have been significantly better when batting first (played three, won three) than chasing (playing four, lost three), and perhaps their use of the Impact rule is a reason behind that. As the conclusion to Sunday's game confirmed, the rule has suited some teams much better than others.