Me playing Poker D.
This map is quite different from other defense maps because in this one the luck is an important factor, though it isn't decisive.
You should try and get at least a fullhouse or better.
Forget about pairs and three of a kind, they do nothing, the only good thing about getting 1 pair is that you get Sarah, and you can use her to lockdown the first boss. lol

But as I said, try to get at least a fullhouse. If you get enough terran mech, then you can just upgrade them and win easily.
Another way to win this is focusing on getting the nexus before round 7, if you do so, you will win, unless you keep getting pairs each round. lol

And... well, I've played this map quite a lot and I've never been able to get a battlecruiser. I'll keep trying, I may get it one of these days.
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https://www.youtube.com/watch?v=IH0Io8oosYg