It is a somewhat common theme for me. I’m not sure that it’s always for the same reasons. If it’s not one thing, it’s another.
I find that against the opponent I play, most are a lot less likely to call if it puts them all in. So I tend to size my bets to a fraction of their stack, and get as much value out of the hand as I feel they’re willing to give me when I have an effective nut hand. Maybe I should be more cutthroat and just put them all in, but usually that ends up netting me less value. Still, in a HU SNG, it’s the KO you’re going for, not winning hands. It’s just that, once I wear my opponent down to where the stack ratios are such that you shouldn’t fear playing any two cards against the small stack, just get them all-in and win a showdown, I can’t seem to do it. The coin flips tails 5-6 times in a row, or I get ridiculously bad cards like 42o, and then I can’t do it. Right up until that point, I’m hitting two pair, straights, top pair, you name it, and just when I should be able to put them away, they start a miracle comeback.
So, I agree with you, maybe it’s my bet sizing, but how do I get opponents to be more willing to go all-in to call against me? I’m generally betting by the size of the pot, should I be sizing bets relative to my opponent’s stack instead?