For most tournaments our standard tie breaking rules are applied. This may differ slightly in tournaments like F1, MotoGP and our Fantasy games where the scoring works a little differently. You can view the specific tie breaking rules for the relevant tournament on the pool leaderboards page, but here's a breakdown of how things generally work:
In the event of points ties on a pool leaderboard, position is allocated on the basis of higher WP total, then higher MP total, then lower TDM. If scores are still tied after these criteria are applied, the players are adjudged to be tied. TDM is Total Distance from Margin: the sum of the differences between a player's margin predictions and the actual margins.