KJ four handed.

[SossMan]

this becomes a math problem.

You thought he would call with TT-AA and AK and AQ, right?

What is the range of hands you think he would make the initial raise with?
You say he's TAG, and its 4 handed and he's got a pretty big stack, so let's give him a fairly broad range of open raising hands:
55-AA, AK-A9, Axs, KQ, KJ, KTs, QJ, QJs, and an assortment of random medium suited connectors.

Hands that he would raise with, then fold to the all-in:
55-99: 6 ways to make each pair = 30 combos
AJ-A9: 16 ways to make each of these = 16*3 = 48 combos
Axs (really A8s-A2s, since the others are counted already): 4 ways to make each of these: 7*4 = 28 combos
KQ/JQ: 12 ways each = 24 combos
KJ: 9 combos
KTs, QJs: 3 ways to make each = 6 combos
let's add another 10 or so for suited connectors/ random bluffs.

total = 155 combos of hands that would make the initial raise, then fold to the all in (given your estimation).

Ok...now let's see the hands that he will call with:

AA/QQ/TT = 6 ways * 3 = 18 combos
KK/JJ = 3 ways * 2 = 6 combos
AK = 12 combos
AQ = 16 combos
Total hands that he would call the all in with: 52

So, he's going to fold a little more than 3 times as often as he will call (155 - 52), given these paramaters.

Given the fact that you are probably only about an average of 2:1 dog the times that he calls you, I think the all in is okay vs. an opponent with this range of raising/calling standards (What I would determine as a "typical" TAG player)

155 + 52 = 207
155/207 = ~75% of the time, you win uncontested.
25% of the time, you are about a 65-35 dog, so that gives you another 8%-9% equity.
You will lose and be out of the tourney about 15% of the time. You will double up about 8-9% of the time. You will increase your stack by 3.5x about 75% of the time.

Given that he did call you w/ 99, you can probably add in a few more hands into the "call" section (99,88, maybe AJ) and rerun the numbers...I think you will find that it is still decently +EV.

-sossman