Most playoff games before age 25 season, entering today:
Kobe 97
Tony Parker 90
Kawhi 75
Andrew Bynum 74
Ibaka, Darryl Dawkins 71
Magic, Jordan Farmer 69
Rondo, Harrison Barnes 64
JB, Capela, Cory Joseph 61
LeBron 60
Horry 57
Tatum, Harden, Richard Jefferson, BJ Armstrong, Big Baby 55
Most in Conference Final Games before 25:
Darryl Dawkins 24
Kobe 22
Magic 21
Jack Sikma, JB 18
BJ Armstrong, Jordan Farmer 17
Kawhi, Cory Joesph, Westphal 16
Ibaka 15
Jamaal Wilkes, Andrew Toney, Norris Cole, McHale 14
PG13, DJ, Lance Stephenson, Pippen, Horace Grant, Steven Adams, John Salley, Phil Smith, Greg Ballard, Howard Eisley, Tatum 13
FYI, while I didn’t use them for this, Statmuse as linked above is reliable and underutilized at large.