I meant you know you have 2 tricks. Then started to think about criterion that lets me know I have 2 and realize it was a long list.

K9xxx I wouldn't even think I had one likely trick to win.

1) If the A wins I lead the J. If you don't end up winning it probably doesn't matter what you did.

2) If my K is the same suit as the 9 I play it hoping my partner short suited herself and we have a shot at all 5.

If the K is different suit, hmmm. At this point your K is either good, or it's not, no sense worrying about it. If my xx trump are strong (i.e. I can win 2 with just the cards in my hand) I lead the J easily.

If I have JT9, or JQT I would have led the K in the past, given up the lead and re-evaluated. I think now I would lead the 9 or T, you would have a real good idea of where you stood after that.

3) If K is same suit, then I lead the J with strong trump. With weak trump I think you need to lead your lowest trump. Can't lead the K, leading the J is basically a flip like you said (although not a terrible move), so that's the only option.

If K is a different suit it's a little more complicated. I'm leaning towards leading a rag trump (or the J if your trump is strong), for similar reasons.

I look at this situation and think you called it because your hand is awesome and you can win 3 by yourself. So play it as such. If you loose that A you need to start relying on your partner some.