Problem with the Plugin

Which kind of point rules did you choose? DEL or NHL? They have different point rules
Take a look at your ../wp-content/plugins/leaguemanager/sports/hockey.php

If you want to change something you have to do it there in

function getPointRules( $rules )
	{
		// DEL rule
		$rules['del'] = array( 'forwin' => 3, 'fordraw' => 1, 'forloss' => 0, 'forwin_overtime' => 2, 'forloss_overtime' => 1 );
		// NHL rule
		$rules['nhl'] = array( 'forwin' => 2, 'fordraw' => 0, 'forloss' => 0, 'forwin_overtime' => 2, 'forloss_overtime' => 1 );

		return $rules;
	}

function calculatePoints( $points, $team_id, $rule )
	{
		extract($rule);

		$num_won_overtime = $this->getNumWonMatchesOvertime( $team_id );
		$num_lost_overtime = $this->getNumLostMatchesOvertime( $team_id );

		$points['plus'] = $points['plus'] - $num_won_overtime * $forwin + $num_won_overtime * $forwin_overtime + $num_lost_overtime * $forloss_overtime;
		$points['minus'] = $points['minus'] - $num_lost_overtime * $forwin + $num_won_overtime * $forloss_overtime + $num_lost_overtime * $forwin_overtime;

		return $points;
	}

This is the documentaion explanation

function pointRuleDocumentation()
	{
		echo '<h4>'.__( 'German Icehockey League (DEL)', 'leaguemanager' ).'</h4>';
		echo '<p>'.__( 'The DEL uses a more complicated form of the Three-Point-Rule. The winner after regular time gets three points, the loser none. The winner after overtime gets two points and the loser one. This rule was also applied at the Ice Hockey World Championship in 2008.', 'leaguemanager' ).'</p>';

		echo '<h4>'.__( 'National Hockey League (NHL)', 'leaguemanager' ).'</h4>';
		echo '<p>'.__( 'The NHL uses a derivative of the Two-Point-Rule. The winner after regular time and overtime gains two points whereas the loser after overtime and penalty gets one.', 'leaguemanager' ).'</p>';
	}

I solved 0:0 bug with this:
https://wordpress.org/support/topic/zero-in-score-results-and-edit-bug