In this paper we show that sorting different ability contestants in piece rate tournaments into more homogeneous groups alters incentives for agents to exert effort. In particular we show that for a given mean of the tournament group's ability parameters, larger variance (more heterogeneous agents) induces higher optimal effort. This implies that the principal can actually gain from heterogenizing the tournament groups. On the other hand, the effect of this change on growers' welfare is unclear because higher effort leads to higher productivity and hence higher payment, but also increases the cost of effort. Using broiler production contracts settlement data we empirically estimate a fully structural model of a piece rate tournament game with heterogeneous players. Our counterfactual analysis shows that under reasonable assumptions the integrator's gain is actually larger than the growers' losses indicating that heterogenizing groups in piece rate tournaments may be efficient.