overestimate

They came to the conclusion that people with low ability at a task tend to, paradoxically, overestimate themselves.

Here's another example of getting you to overestimate your chances of winning by making subtle changes, because the table is slanted up slightly, which will reduce the horizontal velocity of the ball after the bounce.

And to do that most effectively, they employ a bunch of little tricks to make you overestimate your chances of winning, in some cases to such an extent that it's basically a scam.