Remove misleading KO chance outputs (#536)

This removes a good amount of the text duplication in getKOChance() , but really the point is to resolve #448: where previously 100% chance to be KOed would be returned will instead yield 99.9%, and 0% will instead show 0.1%. I also added a test for the specific case mentioned. I can't think of an example for 0%, but I have seen it before.
smogon · Mar 5, 2024 · 168db24 · 168db24
1 parent f840e76
commit 168db24
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diff --git a/calc/src/desc.ts b/calc/src/desc.ts
@@ -287,20 +287,28 @@ export function getKOChance(
  ? ' after ' + serializeText(hazards.texts.concat(eot.texts))
  : '';
 
+ function KOChance(
+ chance: number | undefined,
+ n: number,
+ multipleTurns = false,
+ ) {
+ if (chance === 0) return {chance: undefined, n, text: qualifier + 'not a KO'};
+ let text = chance === undefined ? qualifier + 'possible '
+ : chance === 1 ? qualifier || 'guaranteed '
+ // prevent displaying misleading 100% or 0% chances
+ : `${qualifier}${Math.max(Math.min(Math.round(chance * 1000), 999), 1) / 10}% chance to `;
+ // using the number of hits we can determine the type of KO we are checking for
+ text += n === 1 ? 'OHKO' + hazardsText
+ : (multipleTurns ? `KO in ${n} turns` : `${n}HKO`) + afterText;
+ return {chance, n, text};
+ }
+
  if ((move.timesUsed === 1 && move.timesUsedWithMetronome === 1) || move.isZ) {
  const chance = computeKOChance(
  damage, defender.curHP() - hazards.damage, 0, 1, 1, defender.maxHP(), toxicCounter
  );
- if (chance === 1) {
- return {chance, n: 1, text: `guaranteed OHKO${hazardsText}`}; // eot wasn't considered
- } else if (chance > 0) {
- // note: still not accounting for EOT due to poor eot damage handling
- return {
- chance,
- n: 1,
- text: qualifier + Math.round(chance * 1000) / 10 + `% chance to OHKO${hazardsText}`,
- };
- }
+ // note: still not accounting for EOT due to poor eot damage handling
+ if (chance > 0) return KOChance(chance, 1);
 
  // Parental Bond's combined first + second hit only is accurate for chance to OHKO, for
  // multihit KOs its only approximated. We should be doing squashMultihit here instead of
@@ -315,28 +323,21 @@ export function getKOChance(
  const chance = computeKOChance(
  damage, defender.curHP() - hazards.damage, eot.damage, i, 1, defender.maxHP(), toxicCounter
  );
- if (chance === 1) {
- return {chance, n: i, text: `${qualifier || 'guaranteed '}${i}HKO${afterText}`};
- } else if (chance > 0) {
- return {
- chance,
- n: i,
- text: qualifier + Math.round(chance * 1000) / 10 + `% chance to ${i}HKO${afterText}`,
- };
- }
+ if (chance > 0) return KOChance(chance, i);
  }
 
  for (let i = 5; i <= 9; i++) {
  if (
  predictTotal(damage[0], eot.damage, i, 1, toxicCounter, defender.maxHP()) >=
  defender.curHP() - hazards.damage
  ) {
- return {chance: 1, n: i, text: `${qualifier || 'guaranteed '}${i}HKO${afterText}`};
+ return KOChance(1, i);
  } else if (
  predictTotal(damage[damage.length - 1], eot.damage, i, 1, toxicCounter, defender.maxHP()) >=
  defender.curHP() - hazards.damage
  ) {
- return {n: i, text: qualifier + `possible ${i}HKO${afterText}`};
+ // possible but no concrete chance
+ return KOChance(undefined, i);
  }
  }
  } else {
@@ -348,22 +349,7 @@ export function getKOChance(
  defender.maxHP(),
  toxicCounter
  );
- if (chance === 1) {
- return {
- chance,
- n: move.timesUsed,
- text: `${qualifier || 'guaranteed '}KO in ${move.timesUsed} turns${afterText}`,
- };
- } else if (chance > 0) {
- return {
- chance,
- n: move.timesUsed,
- text:
- qualifier +
- Math.round(chance * 1000) / 10 +
- `% chance to ${move.timesUsed}HKO${afterText}`,
- };
- }
+ if (chance > 0) return KOChance(chance, move.timesUsed, chance === 1);
 
  if (predictTotal(
  damage[0],
@@ -375,11 +361,7 @@ export function getKOChance(
  ) >=
  defender.curHP() - hazards.damage
  ) {
- return {
- chance: 1,
- n: move.timesUsed,
- text: `${qualifier || 'guaranteed '}KO in ${move.timesUsed} turns${afterText}`,
- };
+ return KOChance(1, move.timesUsed, true);
  } else if (
  predictTotal(
  damage[damage.length - 1],
@@ -391,12 +373,10 @@ export function getKOChance(
  ) >=
  defender.curHP() - hazards.damage
  ) {
- return {
- n: move.timesUsed,
- text: qualifier + `possible KO in ${move.timesUsed} turns${afterText}`,
- };
+ // possible but no real idea
+ return KOChance(undefined, move.timesUsed, true);
  }
- return {n: move.timesUsed, text: qualifier + 'not a KO'};
+ return KOChance(0, move.timesUsed);
  }
 
  return {chance: 0, n: 0, text: ''};

diff --git a/calc/src/test/calc.test.ts b/calc/src/test/calc.test.ts
@@ -1210,5 +1210,27 @@ describe('calc', () => {
  );
  });
  });
+ describe('Descriptions', () => {
+ inGen(9, ({gen, calculate, Pokemon, Move}) => {
+ test('displayed chances should not round to 100%', () => {
+ const result = calculate(
+ Pokemon('Xerneas', {item: 'Choice Band', nature: 'Adamant', evs: {atk: 252}}),
+ Pokemon('Necrozma-Dusk-Mane', {nature: 'Impish', evs: {hp: 252, def: 252}}),
+ Move('Close Combat')
+ );
+ expect(result.kochance().chance).toBeGreaterThanOrEqual(0.9995);
+ expect(result.kochance().text).toBe('99.9% chance to 3HKO');
+ });
+ test('displayed chances should not round to 0%', () => {
+ const result = calculate(
+ Pokemon('Deoxys-Attack', {evs: {spa: 44}}),
+ Pokemon('Blissey', {nature: 'Calm', evs: {hp: 252, spd: 252}}),
+ Move('Psycho Boost')
+ );
+ expect(result.kochance().chance).toBeLessThan(0.005); // it would round down.
+ expect(result.kochance().text).toBe('0.1% chance to 4HKO');
+ });
+ });
+ });
  });
 });