Nice suprise

[Kongobongo]

I saved seeds from a hybrid plant I grew last year.chef's choice.ammana orange is one of the parents apparently.well I grew out four plants this year.upon closer inspection today I find that one of the four plants is producing oxheart type tomatoes.I'm really happy at the find.now,if I keep seeds from the heart shaped plant does anyone know what my chances will be of those plants being heart shaped? Thanks..Will be interesting to see what color these hearts ripen to as the chefs choice are dark yellow.