Solving contest in Ikaros-2013, Greece

One of the events, during the very successful 36th International chess tourney IkariaChess-2013 in Greece, was a Solving Contest. The problems were selected by Mr Dimitris Skyrianoglou and Judge was Ms Marianna Pagali.

The winners are :
1st, Nikolaos Kampanis with absolute score 20/20 and time 1 hour 30 minutes.
2nd, Pavel Kisevel with 19,5/20 in 24 minutes.
3rd, Anastassios Papargyriou with 19/20 in 26 minutes.

Following in rank were : (4th) Athanassios Spiliadis, (5th) Achilleas Kouros, (6th) Alexei Vetyogov, (7th) Chariton Papacharitonos,(8th) Nikitas Georgiadis, (9th) Alexandros Pissias, (10th) Aggeliki Issari, (11th) Georgios Vassilakopoulos, (12th) Evgeny Karganashvili.

And now the problems. Try to solve them. The solution text is visible only when selected.

Problem-718 Vitaly Kovalenko Karpati Igaz, 1968

1k6/1P6/4K3/8/1Q6/8/8/8 (3 + 1) #2, a) diagram, b) wRb4

[a) Key : 1.Qb5! Ka7 / Kc7 2.b8=Q# b) 1.Rb6! Ka7 / Kc7 2.b8=Q# Mate from a square initially occupied by the bK. Theme Umnov. Only (b) was given for solving.]

Problem-719 Boris Pustovoi after K.A.L. Kubbel Molodoo sibiriak, before 1987

5Q2/6pk/8/6KP/8/8/8/8 (3 + 2) #2

[Key : 1.Kf5! 1...Kh6 2.Qh8# 1...g~ 2.hxg6 (e.p.)# Flight-giving key, exposes the wK to check.]

Problem-720 Philip H. Williams Birmingham Post, 1890

8/8/4K3/1kB5/1P4Q1/5B2/8/8 (5 + 1) #2

[Set play : {1...Ka6 2.Qc4#}. Key : 1.Qh3! 1...Ka6 2.Qf1# 1...Kc4 2.Be2# 1...Ka4 2.Bc6# Flight-giving key. Model mates.]

Problem-721 Frederick Gamage 3rd Prize, Western Daily Mercury, 1907

b1k5/2B2R2/8/K1S5/Bp1pp3/5q2/8/2Q5 (6 + 6) #2

[Tries : {1.Bd7+? Kxc7!}, {1.Qg5? [2.Qd8# / Qg8#] Qf6!} Key : 1.Sb7! [2.Sd6#] 1...Bxb7 2.Bd7# 1...Qg3 2.Bxg3# 1...Qf4 2.Bxf4# 1...Qf5+ / Qh5+ 2.Be5# 1...Qf6 2.Bd6# 1...Kxb7 2.Bf4# Sacrificial key. Black corrections. Cross-checks. Exposition of wK to check. Anti-triple for the defenses Qf4-f5-f6.]

Problem-722 Samuel Gold Lasker's Chess Magazine, 1904

8/k7/1pK5/8/8/8/6R1/8 (2 + 2) #3

[Key : 1.Rc2! 1...b5 2.Kc7 [3.Ra2#] 1...Kb8 2.Kxb6 Ka8 3.Rc8# 1...Ka8 2.Kc7 [3.Ra2#] Model mates.]

Problem-723 William A. Shinkman Checkmate, 1901

6ss/2p3K1/8/7k/2B4p/5R2/3B4/8 (4 + 5) #3

[Key : 1.Rc3! [2.Be2#] 1...h3 2.Rxh3+ Kg4 3.Be6# 1...Sh6 / Sf6 2.Be2+ Sg4 3.Rc5# 1...Kg4 2.Be6+ Kh5 3.Rc5#]