Table:
0
A
B
C
D
E
F
G
1
Position
best year
best 2-year period
best 3-year period
best 5-year period
best 10-year period
best 15-year period
2
1
Fischer
Fischer
Fischer
Fischer; Kasparov
Fischer; Capablanca
Capablanca
3
2
Kramnik
Kramnik; Capablanca; Kasparov
Capablanca; Kasparov
Fischer; Kasparov
Fischer; Capablanca
Karpov; Kramnik
4
3
Kasparov
Kramnik; Capablanca; Kasparov
Capablanca; Kasparov
Capablanca
Kramnik
Karpov; Kramnik
5
4
Botvinnik
Kramnik; Capablanca; Kasparov
Smyslov
Kramnik; Botvinnik
Kasparov
Smyslov; Kasparov
6
5
Capablanca
Karpov; Smyslov
Botvinnik
Kramnik; Botvinnik
Karpov; Smyslov
Smyslov; Kasparov
7
6
Karpov
Karpov; Smyslov
Kramnik
Smyslov
Karpov; Smyslov
Fischer
8
7
Smyslov; Tal
Botvinnik; Alekhine
Karpov
Karpov; Lasker
Botvinnik; Spassky
Botvinnik; Spassky; Petrosian
9
8
Smyslov; Tal
Botvinnik; Alekhine
Spassky; Lasker
Karpov; Lasker
Botvinnik; Spassky
Botvinnik; Spassky; Petrosian
10
9
Petrosian
Anand
Spassky; Lasker
Alekhine; Anand
Anand
Botvinnik; Spassky; Petrosian
11
10
Euwe
Tal; Spassky
Anand
Alekhine; Anand
Lasker; Petrosian
Anand
12
11
Spassky
Tal; Spassky
Petrosian
Petrosian; Spassky
Lasker; Petrosian
Tal
13
12
Alekhine; Anand
Lasker; Euwe
Tal; Alekhine
Petrosian; Spassky
Tal; Alekhine
Alekhine; Lasker
14
13
Alekhine; Anand
Lasker; Euwe
Tal; Alekhine
Euwe; Tal
Tal; Alekhine
Alekhine; Lasker
15
14
Lasker
Petrosian
Euwe
Euwe; Tal
Euwe
Euwe
16
15
Morphy
Morphy
Morphy
Steinitz
Steinitz
Steinitz

Questions and formulas:
Question: Which people had the best 10-year period when Fischer had best 15-year period?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:G1,G1="Fischer"),6))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:G16,G2:G16="Fischer"),6))
Level: medium
Question: Which people had the best 10-year period when Capablanca had the best 15-year period?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:G1,G1="Capablanca"),6))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:G16,G2:G16="Capablanca"),6))
Level: medium