where i change the value of points compiled for a win for the league table ?

in include/league-table-item.php file, around line 76, try changing 

$league_table[get_the_title()]['pts'] = ($league_table[get_the_title()]['overall-win'] * 3) + $league_table[get_the_title()]['overall-draw'];

to :

$league_table[get_the_title()]['pts'] = ($league_table[get_the_title()]['overall-win'] * 2) + $league_table[get_the_title()]['overall-draw'];

and save file .  in above code 2 is just example . change it as per need .