Played his first pro game as a 20 year old in 01-02 (Columbus, ECHL), exempt for four seasons 01-02/02-03/03-04/04-05. He has played 15 total NHL games, he will still be exempt next season should he not play more than 65 NHL games this year (it's a safe bet)
Spezza is EXEMPT
Played his first pro game at the age of 18 in the playoff season of 2001-02 (Grand Rapids, AHL), exempt for only three seasons since he played more than 11 games at age 19 (01-02/02-03/03-04). He has played a total of 117 NHL games, still a few games below the waiver limit
Betts is NON-EXEMPT - he must be protected
Played his first pro game at the age of 20 in 2000-01 (Saint John, AHL), exempt for three seasons 00-01/01-02/02-03 ... he is no longer exempt from waivers.