This ればだ is just the ~ば conditional attached to できる and then ended with copula だ. I'm sure there was some context before this which would help us understand the second half of that conditional.
So without the だ, you would just have a first half of the conditional:
無量大数以上の局面をすべて把握できれば
If you can grasp the incredible number of possibilities of the board [...]
But with だ, this would be a rough translation:
無量大数以上の局面をすべて把握できればだ。
That is, if you can grasp the incredible number of possibilities of the board.
Even in english, this sentence cannot stand alone. You need more context. I've added the line before that to the sentence:
原理上、明確な必勝法がある。無量大数以上の局面をすべて把握できればだ。
Theoretically there is a surefire way to win. That is, if you can grasp the incredible number of possibilities of the board.
By reversing the order of these sentences and adding the bolded parts, you get a full conditional, albeit less emphatic than it was before:
無量大数以上の局面をすべて把握できれば、明確な必勝法がある。
Only if you can grasp the incredible number of possibilities of the board, there is a surefire way to win.
Which would make sense, because if you memorized all the possible situations of chess, there is no way you would lose.