Everton boss Roberto Martinez says five teams can win the Premier League this season.
Defending champions Manchester City and Chelsea are favourites in the race.
But Martinez does not believe they will be the only challengers.
He said: "I think the league will be a lot more open than people think, the results last week don't reflect the performances.
"Some were lucky to get their three points, others very much the other way.
"It will be even smaller margins this season and the changes could be huge this season, I think five teams have an equal chance of winning the title.
"It's about how injuries and suspensions hit them at key moments, it's going to be that close I think it will be the tightest league we have ever seen."
