Personal Results

After a year of testing on my Japanese deck from December 2023 with ~30,000 cards learned to December 2024 with ~37,000 cards learned, using Anki SRS Kai over Anki SM-2 has increased my monthly mature (cards with an interval greater than or equal to 21) retention rate from 80.7% to 88%, monthly supermature (cards with an interval greater than or equal to 100) retention from 81.8% to 88.6%, and reduced my daily workload by almost 17%, from ~350 cards to review to ~300 cards to review each day.

Optimizing my deck with FSRS 4.5 produced the following parameters

w = [3.0764, 4.0925, 6.2791, 10.5132, 5.0603, 0.8525, 0.7931, 0.0993, 0.8338,
0.1, 0.9419, 2.0364, 0.1718, 0.4441, 1.3824, 0.0001, 3.9998]

which have later been converted to SM-2 parameters in the custom scheduler code below.

Previous Anki Settings

Daily Limits

• New cards/day: 20
• Maximum reviews/day: 9999
• New cards ignore review limit: off
• Limits start from top: off

New Cards

• Learning steps: 1m 10m 1h
• Graduating interval: 1
• Easy interval: 4
• Insertion order: Sequential (oldest cards first)

Lapses

• Relearning steps: 10m 1h
• Minimum interval: 1
• Leech threshold: 4
• Leech action: Suspend Card

Display Order

• New card gather order: Descending position
• New card sort order: Card type, then order gathered
• New/review order: Show before reviews
• Interday learning/review order: Mix with reviews
• Review sort order: Due date, then random

FSRS

• FSRS: off

Burying

• Bury new siblings: off
• Bury review siblings: off
• Bury interday learning siblings: off

Advanced

• Maximum interval: 1825
• Starting ease: 2.50
• Easy bonus: 1.30
• Interval modifier: 1.00
• Hard interval: 1.20
• New interval: 0.00
• Custom scheduling: empty

New Anki Settings

Daily Limits

• New cards/day: 20
• Maximum reviews/day: 9999
• New cards ignore review limit: off
• Limits start from top: off

New Cards

• Learning steps: 1m 10m 1h
• Graduating interval: 4
• Easy interval: 4
• Insertion order: Sequential (oldest cards first)

Lapses

• Relearning steps: 10m 1h
• Minimum interval: 3
• Leech threshold: 4
• Leech action: Suspend Card

Display Order

• New card gather order: Descending position
• New card sort order: Card type, then order gathered
• New/review order: Show before reviews
• Interday learning/review order: Mix with reviews
• Review sort order: Due date, then random

FSRS

• FSRS: off

Burying

• Bury new siblings: off
• Bury review siblings: off
• Bury interday learning siblings: off

Advanced

• Maximum interval: 1825
• Starting ease: 2.50
• Easy bonus: 1.30
• Interval modifier: 1.00
• Hard interval: 1.20
• New interval: 0.00
• Custom scheduling:

const deckOptions = {
    "日本語": {
        easeReward: {
            minimumConsecutiveSuccessfulReviewsRequiredForReward: 3,
            baseEaseReward: 0.05,
            stepEaseReward: 0.05,
            minimumEase: 1.30,
            maximumEase: 2.50,
        },
        scheduler: {
            enableFuzz: true,
            maximumInterval: 1825,
            intervalModifier: 1.00,
            calculateHardMultiplier: (currentEaseFactor, currentInterval) => {
                return 0.0;
            },
            calculateGoodMultiplier: (currentEaseFactor, currentInterval) => {
                return currentEaseFactor / Math.pow(currentInterval,
0.059729712);
            },
            calculateEasyMultiplier: (currentEaseFactor, currentInterval) => {
                return 0.0;
            },
        },
    },
    "Global Settings": {
        easeReward: {
            minimumConsecutiveSuccessfulReviewsRequiredForReward: 3,
            baseEaseReward: 0.05,
            stepEaseReward: 0.05,
            minimumEase: 1.30,
            maximumEase: 2.50,
        },
        scheduler: {
            enableFuzz: true,
            maximumInterval: 1825,
            intervalModifier: 1.00,
            // Approximation of the default FSRS v4 parameters
            // [0.27, 0.74, 1.3, 5.52, 5.1, 1.02, 0.78, 0.06, 1.57, 0.14, 0.94, 2.16, 0.06, 0.31, 1.34, 0.21, 2.69]
            calculateHardMultiplier: (currentEaseFactor, currentInterval) => {
                return 0.0;
            },
            calculateGoodMultiplier: (currentEaseFactor, currentInterval) => {
                return (currentEaseFactor / Math.pow(currentInterval,
0.024210328));
            },
            calculateEasyMultiplier: (currentEaseFactor, currentInterval) => {
                return 0.0;
            },
        },
    },
};

// Anki SRS Kai code below
// ...

Statistics

The image below is my retention rate using Anki SM-2.

The image below is my retention rate using Anki SRS Kai.