Most chess problem enthusiasists already heard about famous Babson task - in a problem four promotions by the same (usually black) are answered by the same four promotions by other (usually white) pawn. Queen promotion by queen promotion, rook promotion by rook promotion, etc. Today many problems with Babson task exist, e.g. orthodox #4 - that is very paradoxical theme for direct moremover! - it was composed after many unsuccessful attempts of various composers by Leonid Jarosh, many very nice selfmates exist etc.

Various forms of Babson task exist too, for example if fairy pieces are introduced, it can be extended also to these new pieces. Some fairy forms are very suitable for creating Babson task problems, Madrasi beeing the best known. Just have a deeper look at Pat a Mat original by Ladislav Salai jr. with 8 Babson variations!

But this bunch of problems is dedicated to other variation of Babson task. Recently Richard Stanley asked at retros mailing list about problems featuring so called mixed Babson task, it shows promotions by one pawn answered by promotions of other pawn, not exactly matched, but with different pattern. The symbol showing the type of pattern was defined as follows: if x1 promotion is anwered by x2 promotion, x2 promotion by x3 promotion, ..., xn-1 promotion by xn promotion and xn promotion by x1 promotion, then we have n in symbol. For all cycles with lengths n1, n2, ..., ni we set the symbol (n1+n2+...+ni). For example normal Babson task is then of type (1+1+1+1), when promotions are matched cyclically (Q-R, R-B, B-S, S-Q), it is of type (4).

Regarding following problems, four were sent to me by Richard Stanley and 3 are incorrect, but I think in any case they may give light to manner of constructing selfmates with mixed Babson task and possibly encourage composers to try their luck.
 Daniel Itzhaky Comm The Problemist 1977 1.gxf8R! th. 2.exd8~ ~ 3.Rxc2 or Rc1 Rxh7# 1...c1S 2.exd8R (th. 3.Rxc1) Sxd3 3.Rxd3 Rxh7# 1...c1R 2.exd8S (th. 3.Rxc1) Rxc6 3.Sxc6 Rxh7# 1...c1B 2.exd8B (th. 3.Rxc1) Bg5 3.Bxg5 Rxh7# 1...c1Q 2.exd8Q (th. 3.Rxc1) Qg5 or Qxc6 3.Qf6+ Qxf6# 1...Bxc7, Bxe7 2.Rb5+ Be5, Bc5 3.Rc1 Rxh7# Type (1+1+2). s#3 (14+7)

 Daniel Itzhaky 1st-3rd Prize Themes-64 1976NOT CORRECT 1.Sd1! zz, 1...exd1Q 2.f8S Qh5 3.Se6 Qd1 4.Sxd4+ Qxd4# 1...exd1S 2.f8Q Sf2 3.Bd3+ Sxd3 4.Qb4+ Sxb4# 1...exd1R 2.f8B Rh1 3.Bg1 Rxh7 4.Bh6 Rxd7# 1...exd1B 2.f8R Bh5 3.Rf2 Bd1 4.Re2 Bxb3# Type (2+2). Cook: 1.c8S! exf2 2.Rb8 Qxb8 3.Sa7+ Qxa7 and 4...Qxd7# Cook: 1.Ra7! Qh6 2.e6 Qxh2 3.f8Q Qxc7 4.Qc5+ Qxc5# s#4 (12+8) Maximummer

 Daniel Itzhaky feenschach 1981NOT CORRECT 1.Sxd3(pd7)+! 1...dxc1Q 2.gxf8S(Sb8) Qh6 3.Sf4 Qa6 4.Se6 Qd6# 1...dxc1S 2.gxf8R(Sb8) Rf6 3.Rb8 R~ 4.Rb3+ Sxb3# 1...dxc1R 2.gxf8Q(Sb8) Rxh1(Bf1) 3.Qd6 Rxh5(ph2)+ 4.Qd5 Rxd5(Qd1)# 1...dxc1B 2.gxf8B(Sb8) Bh6 3.Bd6 Bc1 4.Bf4 Be3# Type (1+3). Dual: 1...dxc1B 2.Se1 or Sb4 Bh6 3.Sc2+ Kb2 4.Se3 Bxe3(Sg1)# s#4 (8+11) Maximummer Circe

 Daniel Itzhaky 1st HM Probleemblad 1980NOT CORRECT 1.Rg1+! 1...hxg1Q 2.f8B Qa1 3.Bxc5 Qxh1 4.Bg1 Qxh4# 1...hxg1S 2.f8Q Bd1 3.Gf1 Ba4 4.Qf3+ Sxf3# 1...hxg1R 2.f8S Ra1 3.Qd1 Rxa6 4.Sxg6 Rxg6# 1...hxg1B 2.f8R Bd4 3.Rxf3 Bg1 4.Re3 Bxe3# 1...hxg1G 2.f8G Gb6 3.Gb4 Gb3 4.Gxg3 Gxg3# Type (1+4). Cook: 1.Bc6! Gg8+ 2.Kf5 Bxc6 3.Gd3~ Ra3 4.Gf3 Rxf3# s#4 (8+13) Maximummer2+1 grasshopper

 Nils Bakke 2nd Prize Lindgren Jubileum 1992 - section B 1.g7! zz, 1...h1Q 2.g8B Qxc6 3.Bd5 Qxh6# 1...h1S 2.g8R Sg3 3.Rxg3 b2# 1...h1R 2.g8S Rxh6 3.Sxh6 b2# 1...h1B 2.g8Q Bxc6 3.Qc4 b2# Type (2+2). s#3 (8+7) Maximummer

 Daniel Itzhaky 3rd Prize Lindgren Jubileum 1992 - section B 1.a5! zz, 1...cxb1Q 2.e8R Qg6 3.Rc8 Qb1 4.Rc2 Qh1# 1...cxb1R 2.e8B Rh1 3.Bg6 Ra1 4.Bb1 Rxa5# 1...cxb1B 2.e8S Bg6 3.Sf6 Bb1 4.Se4 Bxe4# 1...cxb1S 2.e8Q Rg7 3.Qc6, Qxc3+ Rc7, Rxg3 4.Qc5+, Qc3+ Rxc5#, Sxc3# Type (4). s#4 (8+9) Maximummer

 Horst Bäcker 1st Prize Schach-Echo 1974 1.f7! short threats 2.fxg8Q/R/B/S 1...e1Q 2.fxg8S!    2...Qg3 3.Qe6+ Qd6 4.Qxd7+ Qxd7#    2...Qd2 3.Bxd5+ Qxd5 4.Qxd7+ Qxd7#    2...Qxe3 3.Se7+ Qxe7 4.Qxd7+ Qxd7#    2...Qf2 3.Rh6+ Qf6 4.Sxf6+ Rxb8# 1...e1S 2.fxg8Q! Sxc2 3.Sxc2! a1~ 4.Rxa1 Rxb8#    (2...Sxg2 3.Qxg2 - short, but important) 1...e1R 2.fxg8B! Rxe3 3.Rh6+! Re6 4.Bxe6 Rxb8# 1...e1B 2.fxg8R! Bf2 3.Rxc3! B~ 4.RxB Rxb8#    2...Bd2 3.Rg3! B~ 4.RxB Rxb8# Type (2+2). s#4 (15+9)