- To illustrate this phenomenon, although it's defendable the standard initial
- position allows the attack as 1.Na6 (threatening Nc5-Nd3#),
- forcing the defense Nf3-Ne5. With a knight next to the king you have more options.
+ A less constraining condition would be to require the two knights to stand on
+ two squares of different colors, but it's not enough as proved by the
+ following diagram.
+ White can mate in 3: 1.Nc6 followed by Nb4 threatening both a2 and d3.