Manchester United must prepare themselves to reach a points total in the high 80s if they want to retain their Premier League title. United required only 80 to claim a record 19th championship last term, by an impressive nine-point margin from Chelsea and Manchester City. They have already reached 45 from their first 20 games this season, yet, after successive defeats to Blackburn Rovers and Newcastle United, still find themselves three adrift of City, with Tottenham Hotspur now trailing the Red Devils only on goal difference. Sir Alex Ferguson is not convinced any club will be able to maintain that momentum over the arduous second half of the campaign. However, the United manager acknowledges the demands this term are going to be much greater. \"It could be the high 80s the rate it is going, which is surprising,\" said Ferguson. \"Two or three years back there was definitely a tightening up of the league. \"It became a bit harder and instead of four teams battling for the top positions, you had six, with Manchester City and Tottenham coming into the reckoning as well. That makes it far more interesting for the spectators and neutrals.\" Ahead of tomorrow\'s Old Trafford encounter with relegation-threatened Bolton Wanderers, Ferguson conceded United\'s tricky programme over the remainder of the campaign, including a succession of away matches against nearly all their rivals, makes life especially difficult. \"I don\'t think it is impossible for the final totals to be double the number of points we have now but it is unlikely,\" he said. \"It would be a hard task for the three of us to maintain that kind of consistency and get another 45 points. \"We have very difficult games away from home: Arsenal, Chelsea, Tottenham and Manchester City. That is four massive games. \"Points will be dropped on the run-in. That is the nature of the league and how competitive it is. You just hope you don\'t drop as many as the rest.\"