Sir Alex is delighted with United's red-hot form but feels there are plenty of twists and turns to come in the Barclays Premier League title race.
It may still be too soon to write Arsenal and Chelsea out of contention but the manager continues to be impressed with the job that Harry Redknapp is doing at Tottenham.
"We have plenty of options in attack and I'm pleased with the form," said the boss. "Hopefully we can keep the momentum going. The form is good and the players are enjoying themselves too.
"It's only the end of December," he asserted. "We surrendered a 12-point lead to Arsenal some years ago and won the title despite being 12 points behind Newcastle.
"Last year, in November, Chelsea were so many points clear that they were odds-on. But they hit a bump and we took over. So I think, with some of the games coming up in the second half of the season, you can't say for certain that's going to be the case [Arsenal and Chelsea are too far behind already].
"The difficulty for them is they've got to overtake three teams so, unless the three teams collapse, only that will be an opportunity for Arsenal or Chelsea to take advantage of. As for Spurs, I think they play the best football in the country. The current team, in the form they're in at the moment, is the best in the country."