I agree. This flop smashes the BB’s range way more than ours. If V has 2 pair or a set and thinks we have an overpair he may be shoving for value. Alternatively, V may think this is a c-bet with air and doesn’t expect a call, but probably does have a piece and perhaps a combo draw which could put him ahead of just about all of our range. 

I don’t have very many 4-to-5-times-pot check-shoves in my game so I always struggle to understand the reasoning. I think a big c/r achieves the same thing, but at these stakes I see it a lot. I guess since we cover him he may think it looks weak and more likely to get a call? The other way around I think it may have more pressure than nuts in it?

I don’t know how informative this is, but I entered our likely range from V’s point of view against what I think V might shove with:

H: 38%: 55-TT, AJ, AQ, KQ, QJ, JT, 9T
V: 62%: 4d5d, 5d6h, 57, 8d9h, 9hTd, 9dTd, 4d6h, 5d7*, 5d8d, 44, 99, 66, TT, Ad*d

V’s range above against our exact hand gives V 60% equity. Removing the sets drops this to 52%. Removing TT drops this to 43% (interesting).

…I didn’t spend a ton of time on these ranges, so take it FWIW.

Correction to my reply: You hold blockers to some of V’s combo draws. so this is even more likely to be a scared top-pair, weak over-pair, or two-pair hand, played badly…when it isn’t it could be an over-excited reaction to a nibble and he yanks way too hard on the fishing line. (To be clear I am not calling anyone a fish. I just can’t think of a better visual analogy.) Anyway, revisiting what draws V could have, this reduces the best draw to something like AdJd+, which has a lot of equity against our hand still (we are actually behind):

Hand	Equity	Wins	Ties
77	48.79%	483	0
AJ+	51.21%	507	0

8T actually has 55% but isn’t as likely from EP IMO..
A4 has just under 50% but, again, I think less likely from EP

I think the real problem with calling here is 77 doesn’t have much chance of improving to a better hand when it is behind. Considering the increased probability that V is not on big draw, this doesn’t look like a good spot to me.

By the way, after thinking about it more it occurred to me that I have actually over-shoved two-pair in a multi-way pot on a wet board, but it was early in a progressive KO tourney and the table was wild. I got called too (don’t recall details but I remember winning, FWIW).