This has got to have been my worst defeat ever. The map says it all.
I thought I had a perfect setup...jumps going in opposite directions, so build 4 cols to start out and tricked on five planets. But then I ran into Fighters at 18,20.
He had 2 cols there, but instead of colonizing like I expected him to he moved them both down and was able to colonize 18,19. At the same time he moved a fleet into 18,20 that included a col ship.
By that time I had explored my planets down below and realized that I was in big trouble. I let him colonize both planets to the north, planning to build a fleet with a troopship and take them both back. The problem was, he tricked earlier than I expected...a bad trick as it turned out, but still enough so that my BR-1 troopship couldn't invade. I nuked 18,20, but with his ag he got 18,19 to builder status the next turn.
I tried one last gamble, building a huge fleet before he could explore my Home World. I just didn't have the econ support, though, and his ships killed the entire fleet. Seeing that I couldn't get out to get to my northern planets, and being so occupied that I couldn't get my other two southern planets colonized, I conceded.