I thought this was funny...

Recent blitz game, guy goes for a Berlin (sheesh, seems like everyone plays it now) and then offers (similar to) Marshall gambit by transposition... I LOL

Most booked up Berlin players know that 4. d3 is white's best alternative to the endgame line, so they'll know to prepare for it.

Also, normally you'll see 4... Bc5 or 4... d6 instead of 4... a6 which to me seems inconsistent with 3... Nf6.

Always accept gambits by transposition, it gives the annotator something to talk about.

An interesting idea. Is this semi-marshall correct, does anyone know?

Personally I switched to the Jaenisch from the Berlin mostly because I was sick of the d3 lines. And this may be a breath of fresh air to play against them.