Spliting sugar maple vs. silver maple by hand

I had some of both here in the last couple years.
The sugar maple - I could not split by hand. Green, dry, summer, frozen solid, wedges, none of it seemed to help. I hacked away for a while and gave up. The rounds were 18-24". Finally used a hydraulic splitter. Took some tonnage to chop it up. Sugar maple seems to be kind of branchy, so none of the rounds were really straight grained.
Silver maple - Frozen solid seemed to help. Not sure about the green vs dry part, because by the time I got to splitting most had been cut down at least a couple months. Hand splitting starting at the outside and peal off sections of splits seems to work ok. With that even large 3ft dia rounds can be worked, it just takes time and a process.

Green wood splits easier than dry wood.

Frozen solid makes splitting by hand much easier. Sugar maple is easy to split by hand.

Maple is pretty easy. Silver is easier. Dry wood splits much easier for me, using a maul.

As long as the round has no knots in it both split easy
If there was a branch knot then you are in a world of hurt
But then my hydro don't care it splits anything I throw at it