on the bubble

Smith was on the bubble but lost out when Jones was faster by a tenth of a second.

Most players play pretty loose on the bubble, much looser than they theoretically should, and even if I saw an opponent sitting out a few hands, it's more likely that he just hit a run of low cards than that he turned into a locksmith at this stage.

The new bond issue now appears to be on the bubble, with support eroding.

Among other aspects of bubble measurement, the researchers were interested in measuring the size of the bubble with a laser scattering technique. A laser is shone on the bubble, which scatters the light.