I don't know if this applies to you as well but I had the same issue so I posted the last hand where I'd done this (89s – it's in the mtt strategy forum) and yeah similar circumstances it was deep I had a tonne of chips etc. I think this also applies to the helping control aggression thread.

Basically after really analysing the hand and the play I realised that there are a specific set of circumstances which lead me to do this.

1 – I have a lot of chips (either cl or 2nd at the table)

2 – I perceive the other big stack to be a weak player (unlike me at this point in the tourney – I'm going to crush it and head to vegas)

3- I normally have air or a horribly marginal hand (see 89 hand)

4 – They normally show a little stregnth early on and then back off – at which point  I decide their hand is weak and I can push them off it

I realised that the reason I get to this point is that most of my perceptions are correct – apart from the one in bold 🙁

The hands are normally extremelly marginal.

But they're the type of player that just never lets go – and not because their astute, thinking and pot controlling – more because they're a bit station like and have a tonne of chips! I'm never going to get these guys to fold so I now look for the warning signs when I get into a hand and am thinking of bluffing – do I think the player's weak, do they have lots of chips, have they shown stregnth followed by weakness  – and I generally try and check/fold it down.