After 2012's record of seven different winners from five different teams in the opening seven races, Alonso thinks '13 will deliver fewer underdog shocks but a remarkably close lead battle.
"No one knows who can win this race at this moment," Alonso said. "We have to answer some questions that winter testing never answers.
"It maybe is not the same as last year when we saw seven winners in seven races and it was mixed. This year with consistency in the rules I expect five top teams to have a little advantage and not to have many surprises in the first five races.
"From these top five it is hard to see who has the extra two or three tenths that can make you win. Now it is hard to choose one favourite.
"Mercedes, McLaren, Ferrari, Lotus and Red Bull showed some potential on different days in testing and in different races last year. I think it's difficult to choose."
Alonso reiterated his confidence that Ferrari is in a substantially better position than 12 months ago, when it suffered a dispiriting testing performance.
"I think it was not difficult to start better than last year, it would be difficult to start any worse," he said.
"Winter has been much better than last year in understanding the car and working with the car and getting the results we more or less expect. This gives us confidence and optimism to start the season.
"We arrive here with 100 per cent of the potential of the car. Hopefully it is enough to be competitive."
He denied that losing the title at the final round in two of the last three seasons made him extra motivated for 2013.
"I feel privileged to have fought for the championship two times in the last three years," Alonso said.
"Not many people have chance to be on the podium and enjoy podium ceremony, fewer win races and even fewer are in a position to fight for the championship.
"We want to again have the opportunity to fight for it this year. We want to change the result.
"It's a normal thing for the sport and maybe it gives some extra motivation for me and the team to really have one happy result at the end."