[Retros] destination squares

[Mario Richter]

> 1. Find the longest game of chess (not necessarily ending in mate) with

>     only two destination squares.


There is exactly one game of maximum length.


> 2. Find an infinite game of chess with three destination squares.


It's clear that only the two queens can do the infinitive dance.
But there are several triples of destination squares that do 
the job.

  mario