Brendon McCullum's batting style and his attitude is ideally suited to the limited-overs format: he isn't afraid to go after the bowling from the first ball, his range of attacking shots matches his attitude, and he hardly takes a backward step during a contest. All of those skills were on display in the 2015 World Cup, when McCullum's aggressive batsmanship at the top of the order combined with his flair and aggression as leader to take New Zealand all the way to the final. His strike rate in the World Cup was 188.50 (328 runs from 174 balls), the best among 87 batsmen who faced at least 100 balls in the tournament. If you reduced the cut-off to 50 balls, his strike rate was still the best.
McCullum seems to have carried that form into the IPL, for in his second innings of this tournament he carted the bowlers from Sunrisers Hyderabad all over Chepauk in scoring an unbeaten 100 off 56 balls. That's his second IPL century, following on his unbeaten 158 off 73 balls in the very game of the very edition, in 2008. That knock had announced to the world the limitless possibilities for batsmen in this format, and McCullum remains one of only six batsmen to score multiple centuries in the IPL.
Despite these skills which seem ideally suited to limited-overs cricket - and even more so to the 20-over format - McCullum's record in the IPL is underwhelming: before the start of the eighth season, he had scored 1644 runs in 62 IPL innings at an average of 28.34, and a strike rate marginally under 123. The strike rate is the surprising number, for out of 27 batsmen who've scored 1500 or more runs in the IPL, McCullum is ranked 21st in terms of strike rate. That's hardly consistent with his reputation or his skill.
Apart from the two hundreds he has scored, McCullum has only one other IPL innings where he has faced 20 or more deliveries and scored at a strike rate of 150 or more. Chris Gayle, on the other hand, has 20 such innings over the first seven seasons of the IPL; Suresh Raina has 22, while Virender Sehwag has 21 innings of 20 or more balls where he scored at a 150-plus strike rate, in the first seven editions of the IPL. McCullum had exactly two such innings before the start of IPL 2015, which indicates the extent to which he has underperformed in previous editions of the tournament. Exclude that unbeaten 158, and his strike rate drops to 117 in 61 innings, which is in the Ajinkya Rahane and Rahul Dravid territory.
(All IPL numbers are for the first seven seasons only - ESPN Cricinfo)