On Monday Tiger Woods split with his instructor Sean Foley, marking the end of what was essentially the fourth era for his ever-evolving swing.
It started with Butch Harmon, Phil Mickelson's current instructor who Tiger began working with in college, and who oversaw Woods' first major swing overhaul in the latest 1990s. Before ending their relationship in 2003, the pair won eight majors together. Woods' swing in the first GIF is during the 2000 U.S. Open at Pebble Beach.
The second GIF is Tiger's swing under Hank Haney, who he won six majors with between 2005 and 2008. It's a little more precautionary than his swing with Butch, guarding against that failing left knee he was worried about at the time.
The final GIF is of Tiger's swing at this year's Honda Classic, under the tutelage of Sean Foley. You'll notice his body staying a little more central over the ball, which is one of Foley's keys for hitting good iron shots.