Last year I had one New Big Dwarf grow much smaller fruits than normally. I suspect that there had been a cross made by a bumblebee with Sweet Million or some other cherry tomato. I collected seeds from that plant and this year I grew three plants from those seeds.

One plant has grown a bit taller than New Big Dwarf and it has fruits bigger than cherries.
Two plants are about 1 meter tall and fruits are 1-1.5" wide. One is brighter red and really sweet and the plant seems to be prolific. Other one has more pinkish fruits with thicker skins and taste is more acidic. Both of them taste good, but I like the red one more. I have collected seeds from both of them and I am going to grow both of them next year to see how F3 generation will be. I hope that I could stabilize a sweet dwarf cherry tomato from these seeds.

Great project. I've heard good things about NBD being both tasty and productive. Looks like your Red F2 are quite loaded with fruit.

Awsome