ITM% or Win% may look pretty, but it is a fairly pointless statistic.

If we look at the standard SNG payout structure, we might think to ourselves that 30% ITM is a respectable percentage. It doesnt however tell you that much.

30% with all 3rds is losing money.
30% with all 2nds is still losing money.
30% split evenly between 1/2/3 is still losing money.

30% with all mainly 1st places is winning money.

Like I said. It's a fairly pointless statistic really. You should always be more worried about whether you are actually making a profit or loss.

In essence, look at your ROI% and/or your Hourly Rate.

For Ring games :- the only thing of any relevance is your Hourly Rate.
For SNGs :- ROI and Hourly Rate both worth recording.
For MTTs :- ROI, or sometimes Monthly Rate (even Yearly Rate!).

Ring games, Hourly Rate very much depends on the level you play, so no plateau

SNGs, commonly argued that 44.4% ITM is highest over infinite no. of games. That would lead to something like a 36% ROI being possible in theory, although in reality very debateable. At a high level if you are hitting 10% ROI over a couple of thousand SNGs this is high enough to be considered an excellent player.

MTTs, a good ROI is difficult to pin down as one substantial win can skew thousands of MTT results quite dramatically. Generally I'd say something like 40% ROI for 1000 MTTs or above is good and achieveable. (NB if you are a 'limping to the money' type player then forget it ).