McEnroe collected the Legends title for the third year running after beating Mats Wilander 6-2 6-4 in the final.
"I was playing well. I was hitting the ball clean,” said McEnroe.
“I got a little careless and Mats' concentration is great so he takes advantage of some opportunities when they come up."
Wilander was philosophical after losing to an older opponent.
"John is hitting the ball extremely well. He returns so well," he said.
"I think that's something that has maybe got better with age. It's really hard to find a space in the service box that he doesn't get to.
"He seems to read my serve and he's just a little too good, especially on the big points."
In the Masters final, Australian great Rafter beat Britain's Tim Henman 6-3 6-1 to collect the title for the first time since 2009.
"That's the best tennis that I've played since I've been doing these events," said Rafter.
"I feel like I found something in my game, which is weird at 40 years of age. I feel like I'm actually still working on things.
"I've enjoyed it. I always love being in London with the family and the kids at this time of year. it's been a great week for me."
Henman was impressed with his opponent despite the disappointment of losing on home turf.
"Pat's playing fantastically well. Every match this week, he's shown he's been the best player here," he said.
"He was too good for me, he's serving unbelievable. I could have done everything a little bit better, but the way Pat's playing, his consistent level is very impressive.”