Kohli scores, on average, a net deficit of runs compared to the average player in the IPL, given the situations he bats in.

This is his excess runs in the powerplay in the last 6 seasons.

Excess = above what an average player would score in the same situations.

Contd.

A situation is defined by {over,wickets lost,ground}.

So I sum over all balls faced by Kohli, and subtract from his ball-by-ball scores the average score in that over no, with the same no of wickets lost, and on the same ground.

So, in the powerplay, Kohli is mostly below par

Now, what happens in the middle overs? Kohli does better, but of late, he's been mostly in the negative.

Death overs:

Despite having a high death overs SR, his actual contextual contribution is neither too high nor too low.

In fact, his median contribution per match is -0.71.

The same figure for Pant is 1.69, and 2.56 for Russell.

Now, the common defense of Kohli is that he survives long enough to make up for this, and his net contributions are positive. Again, as @the_kk showed, he doesn't survive into the slog overs frequently enough in 1st inns.

And, we can see his overall match contributions.

His match-wise excess runs are +ve only 37% of the time.

His average excess runs is -0.8. This calculates his net contribution. Including the probabilities of him surviving etc.

And this is his season-wise mean excess runs per match.

Even in his stellar 2016 season, in the red.

So even though his aggregates and averages are high, in terms of team impact, he's at or below par.

Averages don't really matter that much in T20, and T20 batting is a team endeavour.

Kohli is too conservative for T20, and a tad too attacking for Tests. ODIs = balanced.