Correct way to apply BYEs for Tournament

[yongshun950824]

Scenario:

Tournament criteria:

• Size: 8
• Type: Single Elimination
• Have match_game (Match with child)

But would like to handle the case such that a tournament is possible not having the exact size of participants to join the tournament. For example, there are 6 people to join.

Before the tournament starts, I have a Confirm Seeding function so that the tournament only can be started once it is confirmed seeding.

brackets-manager.js/src/types.ts

Lines 23 to 26 in 14df8eb

	/**
	* Used by the library to handle placements. Is `null` if is a BYE. Has a `null` name if it's yet to be determined.
	*/
	export type ParticipantSlot = { id: number | null, position?: number } | null;

From the above code and comment indicate that I have to set opponent as null.

---

Implementation:

To fill BYEs as the mentioned scenario above, I am implemented the UPDATE logic to the database with:

If Stage is Single Elimination / Double Elimination type:

• For the 1st group (group with number: 1) and 1st round (round with number: 1, under 1st group)
  ~ Set match (Opponent1 / Opponent2) as NULL
  ~ Set match_game (Opponent1 / Opponent2) as NULL

If Stage is Round_Robin type:

• For all the groups
  ~ Set match (Opponent1 / Opponent2) as NULL
  ~ Set match_game (Opponent1 / Opponent2) as NULL

---

Question:
Does the implementation above is correct to set the BYEs before the tournament is started, especially for the match_game?

This question is related to one issue I faced now when trying to update the match game's result for the further round which also will reflect updates to the previous match/match game for archiving. I would further elaborate on the issue faced once confirm the implementation logic above is correct.

Thanks in advance.

[Drarig29]

I'm not sure I understand why you want to do things on your own, especially the BYE handling.

If you put null values in a seeding, it should work directly, without you writing code for it.

This should work both with manager.create() and manager.update.seeding().

You can have a look at the test files, and search for "BYE". You'll see a bunch of use cases with BYEs.

[Drarig29]

But based on this commit:

b84e02b

The slot not yet filled is still "To be determined" right?

As I see the match's data is something like:
DATA_1

opponent1: { id: null }

And when match data as:
DATA_2

opponent1: null

indicates BYE.

So how can I make the match data from DATA_1 to DATA_2?

No, a not yet filled slot when a seeding is set with manager.create() creation is a BYE. In the commit you linked, you can see that my assertions are asserting that it's DATA_2.

If you set a seeding with null values at stage creation, it is like if you already knew all the participants which would come and not come so they are set as BYEs.

If you do not want this and you prefer to have TBD ("to be determined", aka. DATA_1) values, then do not set a seeding during match creation (only a size) and use manager.update.seeding(). See the comments here:

brackets-manager.js/test/update.spec.js

Lines 629 to 644 in 89a9cd7

	it('should update the seeding to remove participants', async () => {
	await manager.update.seeding(0, [
	'Team 1', 'Team 2',
	null, 'Team 4',
	'Team 5', 'Team 6',
	'Team 7', null,
	]);
	assert.strictEqual((await storage.select('match', 0)).opponent1.id, 0);
	// In this context, a `null` value is not a BYE, but a TDB (to be determined)
	// because we consider the tournament might have been started.
	// If it's not and you prefer BYEs, just recreate the tournament.
	assert.strictEqual((await storage.select('match', 1)).opponent1.id, null);
	assert.strictEqual((await storage.select('match', 3)).opponent2.id, null);
	});

---

And currently, there is no way for "seeding confirmation" as you say, which would convert TBD to BYE.

If I were to implement this outside of the library, I would recreate the tournament with the final seeding.

Something like this (pseudo code):

finalSeeding = manager.get.seeding(originalStage)

manager.create({
  ...sameConfig,
  finalSeeding.map(convertTBDtoBYE)
})

Do you really need this feature built-in in the library?

[yongshun950824]

Awesome, I finally know the difference between manager.create() and manager.update.seeding().

Previously, I use manager.update.seeding() to add/update seed, so as what you mentioned that the empty slot will be "To be Determined".

Now, I work my Confirm Seeding feature by re-creating the stage via manager.create().

Thanks for the assist.

[Drarig29]

You're welcome! I may add this feature later though because it's a really good suggestion: #131

[Drarig29]

@yongshun950824 I hope you are not too advanced in your work about Confirm Seeding, I just released a solution for you.

I found that's a feature which was really missing. Thanks for all the discussions you open!

https://github.com/Drarig29/brackets-manager.js/releases/tag/v1.4.2

[Drarig29]

Question:
Does the implementation above is correct to set the BYEs before the tournament is started, especially for the match_game?

No it's not correct because you don't handle BYE propagation.

Setting a BYE is not enough: you also need to make an opponent win automatically against a BYE, and such recursively through the upcoming matches.

If you have a BYE against a BYE, then it creates a new BYE, and the upcoming match must be winned by the opponent which is against the created BYE.

So no, your solution is not enough and you may use what I told you instead (recreate the stage to "confirm" the seeding). This will handle all what I said above.