Anon told me yesterday that I should find the closest vertexes of the outer and inner polygons to triangulate holes in polygons. I trusted anon but now I realize I should not have, let this be a lesson to me. In this image, closest reflex vertex is V3, but if you connect a bridge between V3 and V9, you can obviously see it intersects with other edges, causing a problem. So one should find minimum angle, not minimum distance.