50/50 situations in tournaments. Advice?

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I want some feedback on 50/50 situations in tournament poker.I was playing in a live $500 tournament today with about 62 runners, which I had won entry to. Anyway, with about 27 people left,2 and a half hrs in, and with the BB at 700 and SB at 350 and with the average chip count at 14000 chips I find myself under the gun with AK offsuit.I have around 12500 chips. I raise 4000 immediately (yeah, I know,probably too much of a raise) and the guy next to me goes all in. He has the same amount of chips as me,more or less. Everyone folds and it comes round and I call. He turns up 9-9. I catch nothing and bust out of tourney. In the 2 and a half hrs of play I had gone with these 50/50 situations three times. Once with my 9-9 against AK, which I won (ironically) and once with 10 10 against AJ (the other guy with AJ was short stacked so I called his all in raise.
This is the question. Is it bad play to force these situations? I know you have to come through a few of these in most tournies to build a stack, but some people on my table with decent chip counts never got themselves into these situations once. Should I have folded with my AK when the guy went all in even tho I put him on a low pair, which he had? What is the best strategy in these situations in tournies