* Three straight wins enough for U.S. captain Couples
* May consider Ryder Cup captaincy (Adds detail, quotes)
By Simon Evans
DUBLIN, Ohio, Oct 6 (Reuters) - Fresh off his third consecutive victory as captain of the United States Presidents Cup team on Sunday, American Fred Couples intends to step down from the position.
Couples, 54, said he has no desire to shoot for a fourth consecutive win over the Internationals when the biennial competition resumes in South Korea in 2015.
"A three-peat's good enough for me," Couples told NBC after Tiger Woods clinched the decisive point at Muirfield Village Golf Club where the Americans triumphed by 18-1/2 points to 15-1/2, their fifth straight victory at the event.
Couples did not rule out a possible role as an assistant and he may well be in contention in the future for a captain's role at the Ryder Cup but he bowed out of the Presidents Cup with a familiar smile on his face.
The outcome was never truly in doubt on Sunday and certainly not once the Americans got to 17-10 up and needed just one more point for victory.
But a spirited fightback from the Internationals with wins for Adam Scott over Bill Haas, Ernie Els over Steve Stricker, Charl Schwartzel over Keegan Bradley and Marc Leishman over Matt Kuchar introduced some tension.
"Jimmy Gabrielson, who was my main helper in the Presidents Cup the last couple of years and a friend of mine, we were walking around and I must have asked 500 times, 'How are we getting this fourth point, where is the fourth point coming from?'" said Couples.
"And then for a joke, I kept texting Davis (Love III) and Jay (Haas), because yeah, you're nervous. You're nervous, not for the players; the players know what they are doing. But we knew we needed 18 points, and we got them.
"I think it was a very, very good match today, and the matches were all close. At no given time was I a nervous wreck, but it was nice when Tiger ... got the 18th point." (Reporting by Simon Evans; Editing by Frank Pingue/Mark Lamport-Stokes)