What is the best way to test and compare cues for the amount of cue ball deflection they create?

Several testing machines have been built over the years, but the results aren’t always trustworthy. Even with machines, one must be careful with testing procedures. For more info, see CB deflection (squirt) testing machines. Results from some of this machine testing can be found at published squirt data. If you don’t have access to a testing machine or special equipment, a good way to test a cue for comparison purposes for the amount of CB deflection (squirt) they create is to measure the shaft’s natural pivot length.