1) Mavericks vs Heat in the 2006 basketball finals
Dwayne and Shaq. Shaq was the focus in the first quarter, Dwayne in the the 4th. But Wade had trouble with taking over because he was young and Shaq had three championships. They struggled in the finals until Wade got very aggressive with attacking the basket and creating.
Conversely the Mavs go-to guy was Nowitzki, who couldn't force the issue against really aggressive defense because his strength is shooting rather than bulling into the lane and forcing the issue.
2) Celtics 07-08
They struggled against the Hawks (3 losses) and the Cavs (3 losses), al lin very close games. By the time they played the Lakers they had decided who their clutch player was, who their playmaker was. He could fire away at any time. Essentially the Celtics hadn't been tested, didn't know what to do in close games and it cost them a lot. KG wanted to defer to PP, PP wanted to defer to KG. KG knew PP was the better offensive player, but KG was older, more experienced, and former league MVP.
3) USA Olympic Team 2008
KB24 was the senior citizen and a lot of "the peers" were tentative late in the gold medal game. Kobe took over and kept up the aggressiveness. Close games but no losses.
The "take over" player has to be a slasher with aggressive moves to consistently win close games. Look at why LeBron has done so well in the playoffs with a crappy team. They play good defense and he can always, always force the issue by getting to the rim.
The "takeover" player has to be fast, strong, and good at the rim.