Even after rowing in all these pieces, it's often hard to determine who will be selected because the decisive factor in seat racing is speed not margin. Boat X beats boat Y by two lengths over 1000 meters in a time of 2:54. After exchanging "Dave" from X to Y for "Scott," Boat X beats boat Y by one length in a time of 2:51. From the rower's perspective, the result is that Dave beats Scott by a length. But in Mike's eyes, Scott beats Dave because on the second piece, X was three seconds faster-even though it only beat Y by a length.