Jörg Kuhlmann & BDS
The Problemist Supplement, 1998
#3
Sentinels
1.Bg2! f4 2.Bf1[+wPg2] f3 3.g3#
A very simple switchback to create a pawn to mate.
Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) &
CSS/Javascript (jQuery, Bootstrap & DataTables).