The Indian Premier League is around the halfway mark this season with teams scrambling to make the top four of the T20 tournament.

AFP Sport looks at five talking points in the first half of the world's richest cricket competition.

Head starts and tall scores 

Opener Travis Head has been the demolition man for Sunrisers Hyderabad with his explosive starts taking the team to two record IPL totals of 277 and 287 this season.

The Australian left-hander has amassed 324 runs so far including a hundred and two half tons in this campaign.

Head has a strike-rate of 216 in six matches.

At the weekend he smashed a 32-ball 89 to guide Hyderabad to 266-7 against Delhi Capitals and said it was good to be "on a roll".

Impact player rule has... impact 

The impact player rule has been the reason behind the skyscraper totals, with the teams getting a better understanding of how to use it.

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

But it hasn't found favour among some players.

"I am not a big fan of the impact sub rule," said India captain and Mumbai Indians player Rohit Sharma.

"It is going to hold all-rounders back, eventually cricket is played by 11 players, not 12 players."

IPL chairman Arun Dhumal has said the board will review the rule at the end of this edition.

Kohli top, Bengaluru flop 

Virat Kohli has been the lone warrior for Royal Challengers Bengaluru -- he is the leading batsman in the IPL so far with 379 runs including a ton and two half-centuries.

But the former India captain, fondly known as "King Kohli" for his prolific run-scoring, cannot do it all.

His team are bottom of the table with one win in eight matches.

Kohli hit the first ton of this edition but his unbeaten 113 was not enough in a match where Jos Buttler cracked an unbeaten 100 to steer Rajasthan Royals to victory.

Kohli and Bengaluru have never won the IPL and it seems the wait will go on for another year.

Pandya's tale of woe 

Hardik Pandya joined five-time champions Mumbai Indians ahead of this season and replaced veteran Rohit as captain.

The joy was short-lived after the IPL heavyweights lost their opening three matches.

The star all-rounder has been repeatedly booed, prompting commentator Sanjay Manjrekar to say "behave" to the crowd at Mumbai's Wankhede Stadium.

Mumbai have won three of their seven matches, but Pandya's form with bat (141 runs) and ball (four wickets) is a cause for concern.

The lowest point was when Chennai's M.S. Dhoni smashed Pandya for three straight sixes in a 26-run final over.

Starc under pressure of big bucks 

Australia's Mitchell Starc hasn't lived up to his top billing in the IPL with his six wickets and an economy of 12.94 proving costly for Kolkata Knight Riders.

The left-arm quick returned to the IPL after nine years when he became the most expensive buy in IPL history at $2.98 million.

Starc has had his moments, including bowling figures of 3-28 in a win against Lucknow Super Giants.

But he has been guilty of leaking runs at the backend, with his 19-ball last over on Sunday nearly giving away the match to Bengaluru.

Two-time winners Kolkata are second in the table despite Starc failing to properly fire.