Define: Arbitration, Impasse and Clutching

I would like to understand what you guys mean when you talk about arbitration when you talk about trades. Also what does impasse mean when you're talking about the business of hockey and stuff.
And.. what does clutching mean?

So please define:

arbitration
impasse
clutching

Thanks :D

arbitration

http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=arbiter
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=arbitrating
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=arbitration&x=0&y=0


impasse

http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=impasse&x=0&y=0
DEADLOCK

clutching

clutching to me is grabbing your opponent with 1 or 2 hands and trying to gain a positional advantage