I'm the other way around, Egg McDogit. The average length of my bridge is about 7'', but I'm working on lengthening it to 11''. My short bridge length is compromising my play on many kinds of shots, especially in 9 ball.
Between 30 an 35cm on most normal shots. In inches that would be 11.8 to 13.7 exactly. Even on worst frozen to the rail shots my bridge is not shorter than 9 inches.
My stroke length is shorter than my bridge length though. If I see significant blue chalk marks on my bridge hand after playing session, that means I wasn't stroking very well at all.