Two views of gas particles in the bridges of the best and alternate models at ﹩t=120﹩ (top) and 100 Myr (bottom). Membership in the bridge is determined primarily by x‐z position (because the bridge stretch is large in that view). The x‐y views (left) of the two models are quite similar. The x‐z views (right) show that in the best model the gas particles from A promptly fall back to the left‐hand side of the A disk, while in the alternate model these particles are spread across the bridge.