Steve, as you know, all questions like this rely on many factors not included in the question. Dahlia breeding relies on getting the right pollen to the seed pods. People who do not hand pollinate generally try to place pollen plants in near proximity to the target plant. Compared to hand crossing where 98% of the seedlings are actual correct crosses(no method is perfect) relying on bees to do the work , such "targeted' breeding is about 30% less effective in getting the right pollen. Most people give up on the idea of only one possible pollen parent and usually have several willing plants of different varieties near the mother plant. Perhaps they knew(I doubt it) that some crosses are incompatible and you need insurance that a compatible cross will occur. In hand crossing you keep records and can avoid incompatible crosses in the future. My 30% number was computed years ago and was based on our seedlings kept. Since we have many more bee pollinated seedlings(hand pollinating makes limited numbers of seeds). that number is not exactly what you asked. Perhaps 700 "open pollinated" seedlings had a 10% success rate and we kept 70 good ones. Our hand crossed plants probably had a 30% success rate as far as keeping the seedlings but we ended up with only 30% hand crossed seedlings over all as we had many fewer hand crossed seedlings. To repeat, since we had many more open pollinated seedlings, we had many more good seedlings from the open pollinated. This analysis leaves out the fact that our pollen parents in the "open" pollinated areas are now actually many generations of our own breeding and do have concentrated genes in them. Back when I got the 30% rate that was not the case. So as time goes by, in our garden, our open pollinated seedlings have improved dramatically and the difference between hand pollinated and the open pollinated results are less dramatic. Lastly, this leaves out the fact that knowing the two parents with certainty is dynamite information. You can repeat that exact cross over and over. However, you can also, use that information to allow the bees to do that same cross and get lots more seeds. The above information has been rated by the dahlia police as top secret and should not be shared on rival platforms such as Facebook.
Waterlily seedling where it is a single flower but the florets are waterlily shaped and are cupped like a waterlily. Margaret wants to keep this one and I will post another picture showing the cupping better. Comment: We have lots of space to keep anything we like.
