Allardyce and Tony Pulis went to the same school of football management. Unfortunately for Allardyce he doesn't yet have the right players to execute his direct style. They will instead sit back and defend deep, then try to isolate our CBs and break into the space left by our full backs using the pace of Zaha and Benteke.
Because of our last result against West ham, people have forgotten that we struggled to get any fluency in the first half and West Ham, having lost 5 games in a row, collapsed after our first goal. This is a different game, away from home and I think what we need to do given recent away performances is focus on defending again.
A clean sheet at half time means you can take fewer risks, the opposition will eventually come out and leave gaps. A must win game doesn't mean we have to get wreckless again and have our CBs trying to win headers on the half way line.
I get what you're saying and agree to an extent, but I think it'd be dangerous for us to focus on defending.
With Koscielny, I wouldn't trust our boys to focus on the defensive aspect of our game. I feel like we'll eventually give up a chance and knowing us we'll end up conceding. With no Kos and a (talented) rookie in goal in Martinez, we should definitely look to impose ourselves on Palace.
They've got a ridiculous amount of injuries atm, most in the league I believe. The likes of Dann, Cabaye, Remy, Tomkins, Van Aanholt and Souare are all out. They also lost their last game to S'ton despite taking the lead and being on a good run of form. It's time the boys took to the field with some confidence and assertiveness.