ah, Wd4 is a nice move. I have been thinking of Wc5, We4 and Wg5 as some thematical moves with the witch, but I don't remember thinking about Wd4.
Mega-dog Round-1 game (vickalan vs Martin0)
26. Rad1 is essentially winning. This is the first person who has been essentially winning against Martin(except I guess AidanB1 who could have been up a solid pawn)
26. Rad1 Bc7 27. Wc5 looks to me like it wins the guard outright.
Ah yes, 27. Wc5, not 27. c4.
I forgot to check my message history to be fair, I just assumed I'd lost my notes when my computer broke.
Martin is completely right to assess the pawn structure before deciding what the relative value of guard and knight is. But I would say the isolated f-pawn is weaker than the doubled h-pawn. Vick can probably fix his h-pawn problem in time, but that f-pawn will always be isolated, and if Martin can win it, he has two linked passed pawns, easily enough compensation for the guard/knight trade.
But yeah, it does seem like Martin's guard was lost if Vick played accurately.

The simplest refutation to 26.Rad1 Nxf5 is 27.Rxf5. Black loses at least a piece, since capturing on f5 would result in white playing Nxd6 with a fork on e8 and f5.