finished <- data.frame(
    email = as.character(),
    win_percentage = as.numeric()
)


> dput(dat)
structure(list(email = c("kobe@aol.com", "mj@aol.com", "ricky@aol.com",
"tiger@aol.com", "tiger@aol.com", "kobe@aol.com", "mj@aol.com",
"ricky@aol.com", "mj@aol.com", "ricky@aol.com", "tiger@aol.com",
"kobe@aol.com"), game_id = c(5277L, 5277L, 5277L, 5277L, 5278L,
5278L, 5278L, 5278L, 5276L, 5276L, 5276L, 5276L), HomeTeam = c("MINNESOTA TIMBERWOLVES",
"MINNESOTA TIMBERWOLVES", "MINNESOTA TIMBERWOLVES", "MINNESOTA TIMBERWOLVES",
"LOS ANGELES LAKERS", "LOS ANGELES LAKERS", "LOS ANGELES LAKERS",
"LOS ANGELES LAKERS", "CHICAGO BULLS", "CHICAGO BULLS", "CHICAGO BULLS",
"CHICAGO BULLS"), AwayTeam = c("CLEVELAND CAVALIERS", "CLEVELAND CAVALIERS",
"CLEVELAND CAVALIERS", "CLEVELAND CAVALIERS", "SACRAMENTO KINGS",
"SACRAMENTO KINGS", "SACRAMENTO KINGS", "SACRAMENTO KINGS", "TORONTO RAPTORS",
"TORONTO RAPTORS", "TORONTO RAPTORS", "TORONTO RAPTORS"), ATS_result = c(0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1)), .Names = c("email", "game_id",
"HomeTeam", "AwayTeam", "ATS_result"), class = "data.frame", row.names = c(NA,
-12L))