Impact of impact subs - Lower order firepower helping IPL smash scoring records

Better use of the Indian Premier League's impact substitute rule has been the big factor behind this season's run spree in the high-octane T20 competition which has seen multiple scoring records smashed, say experts.

Sunrisers Hyderabad broke their own IPL all-time record score by bludgeoning 287-3 on Monday against Royal Challengers Bengaluru, only three weeks after they set the previous benchmark with 277-3 against Mumbai Indians.

Travis Head led Hyderabad's charge with a 39-ball century, the fourth-fastest in the tournament's 17-season history before Heinrich Klaasen slogged seven sixes his 67 off 31 balls.

"Impact player makes a big difference," Klaasen said after his team's 25-run victory in Bengaluru.

"It's nice to see our boys striking it nicely and our bowlers can at least defend 270, which is always a positive sign."

The impact player rule was introduced last year and allows the replacement of a player named in the starting team at any point after the toss.

The rule is allowing teams batting first to play an extra big-hitting batsman down the order, who can then be replaced by a bowler when they field. Alternatively, a bowler can be replaced if they bat second.

"The impact player rule has definitely worked," former India women's captain Mithali Raj said in a Star Sports press meet on Monday.

Five substitutes can be named and the one used must be Indian, unless there are fewer than four overseas players in the starting XI.

Teams have been using the rule to maximise the chance of quick runs in the final few overs.

"We have seen how it has helped teams to post big totals and... especially it has helped teams in chasing," said Raj.

Hyderabad's total was the second-highest men's score in Twenty20s after the 314-3 scored by Nepal against Mongolia at last year's Asian Games in Hangzhou, China.

Bengaluru fell short by 20 runs after their impact substitute Anuj Rawat hit a 14-ball 25 to help his team finish on 262-7.

The 549-run aggregate in Monday's encounter was the highest in any T20 match.

"It's the intensity that these guys are playing at now, it is the new way. These guys are not frightened," said former England batsman Kevin Pietersen during TV commentary.

Hyderabad amassed their previous record of 277-3 against Mumbai Indians on March 27, but days later Kolkata almost eclipsed it with 272-7 in their 106-run win over Delhi Capitals.

Kolkata opener Sunil Narine led the way with a fearless 85 off 39 balls and Delhi coach Ricky Ponting believes substitutes give the top order extra freedom to play shots.

"I feel the impact players had a bit of an influence on that ," Ponting said after the defeat.

"The fact is that most teams have now got someone reasonably good that can bat at number nine, and sometimes even a specialist batsman at number eight.

"That definitely helps, so it gives the batting team the extra freedom to go harder earlier."

But former India pace bowler Irfan Pathan said there was a flipside to the impact player rule with the role of all-rounders diminishing as they were often replaced after their batting or bowling stint.

"Impact player rule is benefiting entertainment part of cricket, which is high-scoring games," Pathan told reporters.

"But Indian cricket will have to think about it going forward as far as all-rounders are concerned."