Mate in 6

A promising idea is to play 1.Be3?, aiming for a swift Rdb1 and R1b4 mate. Now, for instance, after 1...fxe3? 2.Rdb1 exf2+ 3.Kxf2 Be3+ 4.Kxe3, Black is helpless against the impending 5.R1b4#. However, this plan is thwarted by 1...Bc6!, which simply prepares to counter Rdb1 with Bxb5. Thus, White requires some preliminary measures before embarking on the idea of Be3 and Rdb1.

The solution begins instead with 1.Nd3!, threatening 2.Ne5#. After 1...Kxd4 2.Nf2+!—a switchback—2...Kc4, comes 3.Ng4!, renewing the threat of Ne5#. And here, following the forced 3...hxg4, White finally executes 4.Be3!, threatening 5.Rd4#. Black's attempts to counter with 4...fxe3 or 4...e5 are met with 5.Rdb1!, setting up 6.R1b4#, which now is inevitable.

Note that interchanging the third and fourth moves doesn’t quite work. 3.Be3? fxe3 4.Ng4 can be met with 4...Bf4!, highlighting the importance of the precise move order.