sql server - How to calculate percentages in tsql using a group by query? -

i have table lists results sport , start , end dates , win/loss result. need calculate percentage of wins per sport per season_start. table:

table1 ****** id    sport  won   playerid     season_start  season_end    updated_date ---   -----  ----  --------     ------------ ------------  ------------ 1     rugby   y    kato23       2016-01-01     2016-01-31   2016-02-01 2     rugby   y    king54       2016-01-01     2016-01-31   2016-02-01 3     rugby   n    robby1       2016-03-01     2016-03-28   2016-04-01 4     rugby   y    kelly2       2016-03-01     2016-03-28   2016-04-01 5     soccer  y    kato23       2016-01-01     2016-01-31   2016-02-01 6     soccer  y    jeri44       2016-01-01     2016-01-31   2016-02-01 7     soccer  n    matt24       2016-06-01     2016-06-30   2016-07-01 8     tennis  y    kray43       2016-01-01     2016-01-31   2016-02-01 9     tennis  y    jeri44       2016-01-01     2016-01-31   2016-02-01 10    tennis  n    jeri44       2016-01-01     2016-01-31   2016-02-01 

so i'd run query produces following result:

sport     season_start     success_percent -----     ------------     --------------- rugby     2016-01-01        100.00 rugby     2016-03-01        50.00 soccer    2016-01-01        100.00 soccer    2016-06-01        0.00 tennis    2016-01-01        66.66 

i tried :

select sport,won, season_start, count(sport) sportcount table1 won = 'y' group sport, won, season_start 

but give me entire count not actual success percent. tried using case statement i'm not tsql, or using 'sum' tally wins , losses , calculate win percentage out of total.

can provide tsql query this?

you can use conditional counts this:

select sport, season_start,        sportcount = count(case when won = 'y' 'x' end) * 100.0 / count(*)   table1  group sport, season_start