mate with horse and bishop

can i win with horse and bishop versus king

Okay sure, there have been some recent scandals (but I don't think they're that kinky).

yes you can mate with a bishop and knight. there are many places where you can find the patterns of how to do this. don't call the knight a horse though.

The requirement to force mate with N & B is rare in practice.  Some teachers recommend studying other topics in the time you allot to chess education, suggesting that you will profit more from other subjects.  Others suggest that knowing it and not needing it is better than needing it and knot knowing it.

I recall sweating profusely in an OTB game which almost came down to such an ending.

It's a theoretical win but one of the most difficult to execute, even for master players. It's worth having a look at, even if you don't master the technique, because of the simple fact that you have a good chance of holding a draw even when two pieces down!

It is rare but the technique is educational nonetheless with regards Knight/Bishop, King/Bishop and King/Knight manoeuvres.

I can't imagine that any master player would have a difficult time mating with a knight and a bishop.  

lol, good work.

(I came in here to post "rude")

Don't let me stop you... 

I don't know if I'm surprised that much. It's tricky, add a little time pressure...

It's mentioned in Jesus De La Villa's 100 Endgames You Should Know. From a 4-million-game database, 712 games were KBNvK, 135 of those were drawn (that's almost 20%), some of them Grandmasters according to Jesus.

Exactly.  It can take up to 33 moves even with precise play, depending on the start position.  One slip letting the lone K temporarily escape the net can put you over 50 moves and you are toast.

John Nunn wrote in "Understanding Chess Endgames", page 194: "I have seen grandmasters fail to manage it in rapidplay finishes with 5 minutes left on the clock".