Bilic has been a breath of fresh air. However the points raised by Zippy and others are well founded.
For me the things we need to change are (1) zonal marking (it's just not working; we concede far too many goals from set pieces. One of the biggest criticisms of Moore was that we didn't learn from our mistakes but the same could be levelled at Bilic) (2) Not leaving anyone up the field when we defend a corner (3) having both Phillips and Periera standing together when we have a corner (sometimes it will be a good ploy but not all the time) (4) Trying to score the perfect goal by walking it in, have a shot for god's sake!
1 - I have seen a lot of bashing of 'zonal' marking on here over the last few days, some of which has been unfair (not from you Hull I must add). I saw one comment along the lines of "you always see goals let in as a result of zonal marking" well yeah, that's because it is always highlighted as being a fault of zonal marking. You never hear someone say, that's the problem with the man marking system. I haven't got the time or the will power to start recording goals conceded from corners but would hazard a guess that zonal marking isn't the problem. We conceded shed loads under Mowbray, we marked man for man. I also saw someone say that zonal marking was ok at elite level because the players are better; zonal marking actually benefits smaller teams as it means you can focus your best few defenders of the ball in the most important areas, like Guardiola's Barcelona teams for example. I guess this is just a defence of unfair zonal marking criticism. Regards whether we should change from zonal marking, everyone is right, something must change but for me it is probably a mentality/personnel thing more than a system thing.
2 - I think it is actually a better attacking ploy to have people back behind the ball because when the ball gets cleared, you can press in whatever direction the ball is cleared in, if it goes nowhere near the player up the field then they are just out of the game. You also have forward momentum when attacking the ball when it is cleared. It is very common place for teams to not leave someone up so no problem with this from me. I'll add this in here too as I have seen it elsewhere but I wonder how many times in a season a side that covers both posts have someone on the post saving a goal, not many I'd suggest whereas the additional men can help stop a short corner, cover the edge of the box or help mark but you wouldn't necessarily point out the positive impact of this. Not having men on the post also helps you to attack a ball quicker when cleared and also clear out of the box to squeeze the space for the second phase and the ball back in, it certainly has its plus points.
3 - I agree on this on, not a fan. I understand the logic for free kicks in and around the box as it will influence a defence dropping deep or pushing up depending on whether it is an in or out-swinger but corners isn't the same, only really matters to the keeper.
4 - Amen.