Hgss Catch Rate Calculator

(e.g., Lugia: 3, Magikarp: 255)

None (1.0x) Sleep / Freeze (2.0x) Paralyze / Burn / Poison (1.5x)

Poké Ball / Premier Ball (1x) Great Ball (1.5x) Ultra Ball (2x) Dusk Ball (In Cave/Night) (3.5x) Net Ball (Water/Bug) (4x) Love Ball (Right Gender) (8x) Fast Ball (Speed > 100) (4x) Master Ball (Guaranteed)

Estimated Catch Result

Understanding Catch Rates in Pokémon HeartGold & SoulSilver

Capturing legendary Pokémon like Ho-Oh, Lugia, or the Entei can be a frustrating experience if you don't understand the underlying math. The HGSS catch rate formula (Generation 4) determines whether a Poké Ball will successfully contain a Pokémon based on its HP, status, base catch rate, and the ball multiplier.

The Gen 4 Catch Formula

The game calculates a value called 'a' using the following logic:

a = [(3 * MaxHP – 2 * CurHP) * Rate * BallMod / (3 * MaxHP)] * StatusMod

If 'a' is 255 or higher, the Pokémon is caught instantly. Otherwise, the game performs a series of "shake checks" to determine if the ball stays closed.

Key Factors for Success

• Current HP: Reducing a Pokémon to 1 HP (using moves like False Swipe) significantly boosts your chances.
• Status Effects: Sleep and Freeze are the most effective multipliers (2.0x), while Paralysis, Poison, and Burn provide a smaller boost (1.5x).
• Ball Selection: In HGSS, special balls like the Dusk Ball (3.5x at night) or Kurt's Heavy Ball (which adds flat bonuses based on weight) are often superior to Ultra Balls.

Realistic Catch Examples

Target	Ball Used	HP / Status	Catch %
Lugia (Rate 3)	Ultra Ball	1 HP / Sleep	~4.7%
Red Gyarados (Rate 45)	Net Ball	10% HP / Paralyze	~85%
Rattata (Rate 255)	Poké Ball	Full HP / None	~33%

function calculateCatch() { var maxHP = parseFloat(document.getElementById('maxHP').value); var curHP = parseFloat(document.getElementById('curHP').value); var baseRate = parseFloat(document.getElementById('baseRate').value); var ballMod = parseFloat(document.getElementById('ballMod').value); var statusMod = parseFloat(document.getElementById('statusMod').value); if (isNaN(maxHP) || isNaN(curHP) || isNaN(baseRate) || maxHP maxHP) { alert("Current HP cannot be greater than Max HP."); return; } // Calculation for 'a' value (Gen 4 mechanics) var a = (((3 * maxHP – 2 * curHP) * baseRate * ballMod) / (3 * maxHP)) * statusMod; var finalPercentage; var resultDiv = document.getElementById('catchResult'); var probText = document.getElementById('finalProb'); var shakeText = document.getElementById('shakeProbability'); if (ballMod === 255 || a >= 255) { finalPercentage = 100; } else { // Simplified probability for display: a/255 is the standard capture chance representation finalPercentage = (a / 255) * 100; } // Probability of 4 shakes (successful capture) // b = 65536 / (255/a)^0.25 var b = 65535 * Math.pow((a / 255), 0.25); var shakeChance = (b / 65536) * 100; probText.innerHTML = finalPercentage.toFixed(2) + "% Chance"; shakeText.innerHTML = "Probability per shake: " + (a >= 255 ? "100" : shakeChance.toFixed(2)) + "%"; resultDiv.style.display = "block"; resultDiv.style.border = "2px solid " + (finalPercentage > 50 ? "#4CAF50" : (finalPercentage > 15 ? "#FFC107" : "#F44336")); }