Originally Posted by
fishboat
Nope. The only thing a third watch will do for you is give you a
better estimate of what the time actually is (when the time from all three is averaged).
Au contraire mon frere, perhaps you misunderstand ...
A single watch is for telling time.
A second watch may give you a better estimate of time to the extent it is more accurate than the first and you have both watches side-by-side.
A third watch, even if it provides an extra data point, does not
instantaneously -- and this is the crux -- give you a better estimate of time, because it takes longer to average three data points than two.
Thus, the third and any additional watches are not for improving one's estimate of time, but to collect for admiration, decoration, projecting wealth, signaling taste and/or restraint, and god forbid (for us cyclists), fall detection (Apple Watch).
It is largely analogous to the N+1 rule I often hear about on BF.