<Tr> <Td> Ted Schroeder </Td> <Td> 18 </Td> <Td> 6 </Td> <Td> </Td> <Td> </Td> <Td> </Td> </Tr> <Table> <Tr> <Th_colspan="6"> Longest doubles final match by number of games, before the tiebreaker introduction </Th> </Tr> <Tr> <Td_colspan="6"> 1946, 74 games </Td> </Tr> <Tr> <Td> Gardnar Mulloy William Talbert </Td> <Td> </Td> <Td> 6 </Td> <Td> </Td> <Td> 6 </Td> <Td> 20 </Td> </Tr> <Tr> <Td> Frank Guernsey Don McNeill </Td> <Td> 6 </Td> <Td> </Td> <Td> 6 </Td> <Td> </Td> <Td> 18 </Td> </Tr> </Table> <Tr> <Th_colspan="6"> Longest doubles final match by number of games, before the tiebreaker introduction </Th> </Tr> <Tr> <Td_colspan="6"> 1946, 74 games </Td> </Tr>

What is the longest tennis match at wimbledon