First of all, a corridor - a bet on two arms, both of which may be beneficial. At the same time there is a risk of losing part of the bet. Each corridor has its width. It may be formed in a bookmaker, and in two different. Your task is to see him. Catch convenient corridor is quite difficult. Wide hallway at all rare. Basically, they are formed in the Live-betting when, for example in basketball, one of the long BC responds to precise 3 spectacled throw or unsuccessful attack. In prematche wide corridors often appear on the output line with the "own opinion" (Pinnacle) in one of BC (the line has just published by bookmakers).