West Ham United boss Sam Allardyce admits there's more to buying a player than onfield form.

Most Premier League clubs now have a sophisticated scouting system so nothing is left to chance with players' off-field activities as crucial as those on it in a bid to make sure the 'right characters' are signed.

Allardyce said: "It is not luck - you cannot rely on luck.

"You have got to rely on the information you can gather and try to make a calculated choice that this is the right one for you.

"In January you need to get in what you wanted at the beginning of the season.

"In the summer I wanted six players but, apart from Mohamed Diame, I didn't get them for a variety of reasons.

"When we didn't get any of those six targets we moved on to the next level and the next until we finally got what we got - which was still pretty good talent but they were not the targets we first had in mind.

"All clubs miss out because sometimes they do not know certain players are available to buy or they did not want to come. Then, as it goes on, people do become available and sometimes you take a player and then you get a player come back to you that you have been negotiating with and you kick yourself and think, 'If I had just waited a few days longer'."