he was probably juicing after 2000 or so, watching lesser players like mcguire and sosa get accolades likely drove his ego to "level the playing field" as it were he was 35 in 2000, having already played 7 seasons in sf, so i have to disagree with you to an extent
Most believe he started after that farce season of 98 when Sosa & McGwire were getting all the attention. So I'd have to say it lasted from 99-04. and keep in mind that prior to 99 he had already over 400 HRs over 400 SBs, 3 MVPs & 8 gold gloves.
1999/2000 yeah as a lifelong giants fan im well aware of his accomplishments, steroids or not, one of the best to ever play the game
1 Mantle 2 Guidry 3 Cedeno, Cesar threw a frozen rope from deep center field to 3B in the old Jarry Park in Montreal that I will never forget 4 Winfield 5 Jeter
Look at the side by side season shots... He was a bean pole in Pittsburgh & almost immediately after joining SF, he started looking like a football player...
In his last year in Pittsburgh his numbers were 34 / 103 / 311 in 470 ABs & he led the league in Walks, IBB, Runs, OBP, SLG%, OPS, OPS+ and he won his 2nd MVP So he wasn't exactly a slotch for the Pirates either. But yeah, he did get bigger as the years went on.
Will Clark was one hell of a ball player, remember those Mattingly for Clark Trade rumors. Had the Giants remained in New York they might have been my NL Team. Still respected the franchise after they went to San Fran probably because I entered fandom when Mays, Mantle and Snyder were up in NY, Aaron in Milwaukee and though they did not have the big power numbers other Center Fielders from that era I respected were Richie Ashburn and Bill Virdon.
And when you think of the players the Giants traded away over the years or lost to free agency...........Will Clark, Jack Clark, Willie Mays, Willie McCovey, Juan Marichal, Gary Mathews, Bobby Bonds, Gaylord Perry, Orlando Cepeda. The list of great players are just endless.