Tourney situations - "Checking it down" vs "Raising to isolate"
Okay, prompted by a couple of threads I've seen recently I'm going to attempt a catch-all reponse.
As usual in poker, the optimal play is hugely situation-dependent. To figure out the optimal play, you essentially have to look at what you have to gain by calling a shove from a very short stack and inviting others to come in and 'check it down' and weigh it against what you have to gain by coming over the top of said very short stack and attempting to isolate.
Some people have been intimating in the other thread that one or the other is 'always' correct. This is of course not true.
Considerations, in no particular order:
1) What immediate benefits does eliminating the shortstack have? If there is a significant jump in payout after the next person is eliminated, it's an argument for calling and checking it down. If you're 5 or 6 off the bubble in an MTT, it's an argument for raising to isolate, as you stand to make no immediate gain from eliminating the shortstack.
2) What hand do I have? Obviously the stronger your hand, the more likely it will be you want to raise and isolate. With something like T9s, you will be more likely to want to call and check down simply because (a) your hand is not that strong, (b) your hand isn't good heads-up and you will get most value out of playing it multiway, and (c) as people will be more likely to 'check it down' in these situations, you will likely get free cards to hit any draws that you may flop.
If you have JJ on the other hand, you would be more likely to want to raise to isolate and get rid of any Ax or suited connector hands which could easily outdraw you.
3) How short is the shortstack? If we're dealing with a shorty with 1BB, even if he does double up, he will have to double up a few more times to even be out of the push/fold zone. Thus, there is more reason to isolate the shorter the shortstack's stack is.
4) How much dead money is in the pot? The larger the blinds and the bigger the antes, obviously the more likely it is that you will want to isolate against a shortstack's huge range with dead money in the pot.
5) How likely is it that any other players who are involved or likely to get involved will check it down? If the relevant people have bet with top pair or less in the same situations before, you should be more inclined to raise and force them out of the pot preflop. If on the other hand they have shown they are happy to check down in similar situations, it's more likely that you will want to call and check down.
6) Are you in any danger of going out soon? This sort of ties in with #1, as the more comfortable you are the less tangible benefit there is to eliminating a shortstack, and thus the more inclined you should be to raise to isolate. Factoring in the consideration of the fact that you can use a big stack to abuse the table much more freely in a bubble or big payout jump situation, especially when there is a very short stack around just reinforces this.
I'll post a couple of really obvious made-up examples just as illustration.
(a) Blinds 1k/2k, 100 Ante
Seat 1: 2.5k
Seat 2: 18k
Seat 3: 12k
Seat 4 (you): 19k
Seat 5: 55k
Seat 6: 22k
Seat 7: 9k
Seat 8 (SB): 32k
Seat 9 (BB):19k
5 off the bubble in an MTT
Seat 1 pushes, Seats 2 and 3 fold, action on you with AKs.
Really easy, we shove to isolate here. Most likely we will end up HU with seat 1 who has a huge range, including any Ace and any King, all of which we're crushing. There's ~3500 in dead money in the pot and Seat 1's shove is for 2500, so it is obviously in our interest to isolate with so much dead money to win. As there are 5 left to the bubble, there is no immediate benefit to checking it down. Limping also represents quite a significant hit to our stack, and we don't want to invite hands like QJs etc in which can really easily outdraw us. Finally, even if shorty beats us, he's still critically shortstacked.
(b) Blinds 1k/2k
Seat 1: 7k
Seat 2: 33k
Seat 3: 80k
Seat 4: 21k
Seat 5: 9k
Seat 6: 34k
Seat 7: 33k
Seat 8 (SB): 32k
Seat 9 (BB - you): 44k
On the bubble in an MTT.
Seat 1 pushes for 7k, seats 3, 4, 6, and 8 all call. You have KQs in the BB.
Obviously this is a call and try and check it down (unless you flop something huge) situation. I'll leave you to think about the many reasons why.