I think I covered this to death in the KK thread just a bit ago, but it's a similar preflop situation. If his 3b stat for Bb is that high at this stack size, and not in actuality lower this deep (for instance, my 3b range 150bb deep from bb is much different than my 3b range 20bb deep). But if it is that high,- it's incredibly wide. There are 120 combos of hands that make up the 9% figure. TT+/AK is only 3.5% for instance. Add AJ+AQ, KQ, 88/99 and we still only have 106 combos. I don't really know his general strategy so I can't necessarily comment on it being good or bad, but this is ridiculously exploitable. Like 42 of his hands don't have a pair on most flops, and he's out of position. 40% of his range is air on most flops! 17% of his range (88-TT) is going to dislike a bunch of flops and won't have better than top pair to the board.  

I wanted to back to the main point sorry lol. If his range is this wide, and you then 4bet him, his range does not remain the same if he puts money into the pot. He's likely not going to 5b with 88-JJ or AJ/AQ or KQ, no matter what size you make the 4b. So you've reduced his raising range down to QQ-AA, maybe AK. Those hands only represent 34 hands of his preflop range, or 32% What happens the other times? Well, right away we know that AJ/KQ both have to dislike their hands and fold (and be correct to, if youre 4b range here is only KK+, as even with a nearly 4:1 price pre, hes never realizing his equity since more money goes in postflop and his current equity is a static run out of all finite hands played out and accounted. So anyway back to the 3b/f range. If he folds AJ/KQ that's 31% of his range. If he calls with the rest, that's about the same. So he continues with 32% where you're doing just swell against (I mean… AA> all), he continues passively with a range you're crushing but again, he's not happy with his hand necessarily, he knows he has some sdv or that he needs to improve, so you likely won't even get a ton of money from him anymore).

If you call, though. You get to keep 100% of his 3b range in. The pot's 375 and you get a continuation bet almost always (I imagine his cbet after 3b is quite high if his 3b from bb is this high). If he cbets 80% of the time and cbets half pot, you expect to get 152 chips more. That means you only need to get an additional 18 chips (1bb!!!) out of him somewhere in the hand to make passing on your 4b in favor of calling the more ideal option. He's going to have a ton of marginal strength hands on a lot of run outs because his 3b range is so wide. We didn't even give him 9% of hands initially and already we see his hand strength deteriorates. I don't think running further math to illustrate that higher return you'd see by simply calling, as the work we have so far shows you potentially need to only generate 1bb more, and we're in a much better position to make money. Is his turn cbet and river cbet after 3b% high? 1500 hands isn't very many, but you should have a lot of spots that you can kinda look at his hands instead of having exact numbers. If you see he 3bets 88 in the bb, for instance, then you cover a ton of what I said simply because the rest of the range is within 88 and the top.

Summary- calling appears to net you a higher return than 4betting, especially if you 4b small when you do 4b. His range is so wide that unless he goes crazy when pushed on, you're cutting a ton of potential value away by 4betting. This happens because his range is then cut up. I understand the temptation to induce further action when you see an aggressive player act while you have the nuts, but if playing back is going to cause him to stop (and it will), then it makes more sense to let him have the lead.