Someone

      $ret = array();
      foreach($users as $user) {
          $row = array('Name' => $user['display_name'], 'Total' => $user['staking_balance'], 'Bankroll' => $user['bankroll']);	
          foreach($user['Players'] as $p) {
            $row[$p['Site']['name']] = $p['staking_balance'];
          }
          //set defaults for no links
          foreach( array('PokerStars', 'Full Tilt', 'Ultimate Bet') as $siteKey) {
          	if ( ! array_key_exists($siteKey, $row))
                $row[$siteKey] = 0;
          }
          $ret[] = $row;
      }
      return $ret;