As Harold Lang's biographer, I did have to chuckle over Bob's
miserable period of time as understudy in the 1952 Pal Joey,
showing up faithfully for each performance hoping just once
Harold would have a bad cold or (even better) break a leg.
Harold himself would tell me with great glee years later how
the then-unknown Fosse whiled away his time in the basement
of the Broadhurst Theatre, choreographing dance numbers with
the chorus girls for fun because Harold showed up for the
entire Pal Joey Broadway run... all 542 performances.
Payback would come later -- Harold would never get a
part in a Bob Fosse choreographed or directed show.