It was a hybrid processor, 16 on the inside 8 bit on the bus. From Wikipedia.

The Motorola 6809 ("sixty-eight-oh-nine") is an 8-bit microprocessor with some 16-bit features. It was designed by Motorola's Terry Ritter and Joel Boney and introduced in 1978. Although source compatible with the earlier Motorola 6800, the 6809 offered significant improvements over it and 8-bit contemporaries like the MOS Technology 6502, including a hardware multiplication instruction, 16-bit arithmetic, system and user stack registers allowing re-entrant code, improved interrupts, position-independent code, and an orthogonal instruction set architecture with a comprehensive set of addressing modes.

"Board games" here means go (and only it?)

I honestly was hoping for some tabletop eurogames or smth...

I think of the 6809 as a 16-bit microprocessor, myself (pace Wikipedia). It has 16-bit registers, load/stores, and add/subtracts. A nice clean architecture for its day.