Laddera FAQ

Key Concepts in Table Tennis World

Table Tennis World is organized similarly to real-world structures, making it easy to use and navigate. Here are some key concepts to understand:

• World, Region, Club, Ladder, Tournament, Group: These terms refer to groups of players ranked by their points. They are all have similar layout as shown above. Key distinctions include:
  • Table Tennis World: The overarching structure that contains various regions (optional), clubs, and tournaments.
  • Club: A club can host multiple ladders and tournaments.
  • Tournament: Tournaments can be structured as round-robin, playoff, or mixed formats.
• Player/Member: A player is a user of the platform, which can include roles such as administrator, player, reporter, etc. A single player may belong to multiple clubs, ladders, and tournaments.
• Match: A match, whether singles or doubles, must be associated with a ladder, tournament, or club.

Quick Start Guide

1. Sign up for an account (using "Sign in" link in the top bar)
2. Activate (using the link in the invitation email) and Sign in. Update your profile & skill level (in your home page)
3. Search for a club:
   1. Put the Club's name in the search bar at top, click Search
   2. Or browse in the list of clubs (Laddera's home page, -> tab Clubs)
4. Join a club:
1. Open the club page, -> Members tab
2. Click Join this club
5. Or Create your own club & invite people to join.

That's it! Now you can play matches, submit results and see your rating and ranking updated after every match.

Note:

• Skill level must be updated before submit any match result. Player or admin can update member's skill level in the player's profile page.

Create a Club, Ladder, or Tournament

You need to create a club first before creating ladders or tournaments.

To Create a Club:

1. Log in to your account.
2. From the Laddera home page, go to the Clubs tab.
3. Click on Create Club, Create Ladder, or Create Tournament.

Fill in the form. You can leave most fields as default. However, there are some fields you should pay attention to:

• Name: You don’t need to include "Table Tennis" or "Club/Ladder/Tournament" in the name.
• Privacy: This setting determines how others can view (information, rankings, matches, posts) and join your group.
  • Public: Non-members can view and join your group.
  • Approval: Non-members can view but need your approval to join your group.
  • Private: Non-members cannot view the group and need your approval to join.
• Notes:
  • Regardless of the privacy setting you choose, no one can see members' email addresses.
  • Pending memberships are shown in the Rankings tab. The admin will receive a notification email for membership requests (opt-in).
• Avatar URL: Provide a link to the image. It should start with http:// and end with .jpg, .png, or .gif.

To create a ladder/tournament

• Create your club first, if not yet.
• Open your club page, go to Ladders or Tournaments tab.
• Select either Single or Double.

Notes:

• Club is a ladder itself so you can create/submit match result directly to the club.
• You should create child ladders only when there are many members in the club and you want separate ladders for specific groups (e.g., kids, women, over 60, etc.). You can create ladders anytime, either right after the club is created or later.
• If you have already created a ladder, you can convert it to a club (with permission).

• All matches must belong to a group (club, ladder, tournament, or world). Players need to be in the same group to participate in a match.
• Only administrators or approved members can submit match results.
• Once a match result is submitted, only the group's administrator can delete it.

To submit a match result:

Matches for open league (matches are not generated yet)

1. Navigate to the club, ladder, or tournament that the match belongs to.
2. Go to the Results tab.
3. Click on the Submit Match Result button.
4. A new page for the match will open. Select the match options:
   • Single Match
   • Double Match
   • Practice: Practice matches have less importance, so points won/lost will be lower.
   • League: League matches have greater importance, so points won/lost will be higher.
5. Select players from the dropdown lists.
6. Select the match score in terms of how many sets were won (e.g., 3-1 or 0-3). (You don’t need to submit the score for each set.)
7. Click Submit, double-check your entries, and then click OK.

Matches for organized league, tournament (matches are already generated)

1. Navigate to the league or tournament, locate and open the match
2. Players and other information are already there. We just need to put in the score and submit

Laddera Rating System

The Laddera rating system is based on the Elo model, with enhancements to address some of its limitations.

Initial Rating

Players receive an initial rating based on their skill level, as assessed by a club administrator when they join. Points increase with each match win and decrease with each loss.

Points Calculation

The number of points gained or lost in each match is determined by the Elo Rating System. This calculation depends on factors such as the importance of the match, the player's match history (K-factor), and the rating difference between the two players. It does not take into account the margin of victory or defeat.

Point Rewards

Players earn additional points for participating in matches, regardless of the result, with up to +1 point per day based on their level.

Point Deductions

If players do not participate in any matches for 15 consecutive days, they will be deducted 1 point per day.

This system encourages consistent play and active engagement while maintaining a fair and balanced rating process.

How to use the rating system?

Submitting Match Results

After each match, the winner is responsible for submitting the match result . If the winner is unable to do so, the other player or an administrator should assist in submitting the result.

Match Importance Factor

The importance of the match is determined by the match type:

• Practice Match: 0
• Open League: 1
• Organized League: 2
• Tournament: 3 - 4

Practice Matches

Practice matches are intended for skill development only. No player points will be deducted as a result of these matches.

Match Format

The standard match format for the ladder is best of 5 sets. However, players may agree on a different match format if desired. If the players cannot reach an agreement, they must adhere to the standard format.

Understanding Elo Rating System

The Elo rating system is a method for determining the relative skill levels of players in games like chess, esports, and other zero-sum games. It assigns a numerical rating to each player, and updates that rating after each game based on the outcome and the opponent's rating.

The amount of points gained or lost in each match depends on the adjustment factor "K" and the difference between your points and your opponent's. It does not depend on the margin of victory or defeat.

• Winning Against Stronger Opponents: If you beat a stronger player, you will earn more points. Conversely, if you defeat a weaker player, you will earn fewer points.
• Adjustment Factor "K": This represents the maximum number of points a player can win or lose in a match. The value of K is influenced by the importance of the match and the number of matches the player has participated in. For example:
  • The K value for a tournament match is greater than that for a league/practice match.
  • For league matches, a player's K value is initially 220, which is reduced to 16 after they have played 10 or more matches.

Example:

Consider four players (A, B, C, D) in our ladder:

• A: 500 points
• B: 500 points
• C: 900 points
• D: 100 points

Assuming the K factor for all players is the same: 220.

• If A beats B: A gains 110 (K/2) points, and B loses 110 points.
• If A beats C: A gains approximately 200 points, and C loses 200 points.
• If A beats D: A gains only approximately 22 points, and D loses 22 points.

If you’re interested in the math behind this system, you can learn more about the Elo Rating System.

Important Notices:

• Reward: In addition to Elo points, each participant is awarded 5 points for playing a match.
• Deterioration: If a player does not participate in any matches for 30 days, their points will be deducted by 20 points each week until they start playing again.

Doubles Points Calculation

Doubles have their own separate points, calculated similarly to singles points, using the same Elo rating system.

When two players, say P1 and P2, compete as a doubles team for the first time, their doubles points are the average of their singles points.

After that, the doubles points for the team (P1, P2) are updated based on their match results, using the same method as singles points.

Important Notes:

• The doubles points for (P1, P2) are not related to the doubles points for (P1, P3).
• Once the result of a doubles match involving (P1, P2) is submitted, not only are the doubles points for the pair (P1, P2) updated, but the singles points for P1 and P2 are also slightly adjusted.

Example:

Consider four players: P1, P2, P3, and P4 with the following singles points:

• P1: 500 points
• P2: 600 points
• P3: 700 points
• P4: 800 points

If they play a doubles match for the first time where (P1, P2) upsets (P3, P4), their singles and doubles points will be calculated as follows:

Before the Match:

• (P1, P2)'s points before the match: (500 + 600) / 2 = 550
• (P3, P4)'s points before the match: (700 + 800) / 2 = 750

After the Match, According to Elo Guidelines:

• (P1, P2) are rewarded approximately 150 points:
  • (P1, P2) points = 550 + 150 = 700
• (P3, P4) lose approximately 150 points:
  • (P3, P4) points = 750 - 150 = 600
• Individual adjustments:
  • P1's points: 500 + (150 /