Progression and rating
Algebro has three independent progression systems: account level (XP), Elo rating (ranked skill) and per-domain adaptive levels.
Account level and XP
How you earn XP
For each correct answer:
- 10 XP base
- +5 XP if the question level is ≥ 6
- +2 XP for a fast answer (under 60% of expected time)
For a wrong (but not skipped) answer: 1 XP.
After finishing a series: +50 XP bonus (SERIES_COMPLETION_XP).
After a completed daily challenge: extra +100 XP (DAILY_COMPLETION_XP).
The same XP rules apply to 1v1 duels — playing a duel awards XP for your answers plus the series-completion bonus (duels do not affect Elo rating).
Level thresholds
Account level grows with total XP. Threshold for level n:
XP(n) = 125 × (n−1)^1.85 + 125 × (n−1)
Level 1 starts at 0 XP. Higher levels require progressively more XP.
Day streak
Playing at least one session per day builds a day streak. Any mode counts — Quick play, Training, Exam, Ranked, Daily challenge, or Duels. Missing a full day resets the streak unless a streak pause token activates automatically.
Your current streak is always visible in the sidebar. The flame changes colour and animation as your streak grows (gray → red → orange → gold → blue → cosmic violet at 30+ days).
Activity alert
If you have an active streak but have not played yet today, a red badge appears on the flame in the sidebar — a reminder to extend your streak before midnight. The badge disappears after your first session of the day.
Streak pause
On your profile you can buy pause tokens with XP (7000 XP each, max 2 held). If you miss exactly one day, one token is consumed automatically and your streak continues.
Habit calendar
Your profile sidebar shows a monthly activity calendar — highlighted days are when you completed at least one session.
XP rewards
- Streak multiplier: each streak day (up to 7) adds +5% XP from sessions — up to 1.30× at day 7+.
- Milestones: first time you reach 7 days → +150 XP bonus; 30 days → +500 XP bonus.
When you finish the first series of the day, the counter ticks up and a short celebration animation appears.
AI Coach
The AI Coach praises consistent streaks in reports. After midday, if your streak is still unextended, the Coach page offers a friendly rescue reminder with a link to a quick session.
Elo rating
Starting point
New players start at 400 rating (Novice league).
How rating changes
Rating works like chess — each question is a “match” against an opponent whose strength matches the question difficulty level:
- Level 1 ≈ rating 400
- Each further level: +70 points (
RATING_STEP) - K-factor: 24 (
ELO_K)
Correct on a hard question → big rating gain.
Wrong on an easy one → big loss.
Rating changes in Quick play and Ranked. Ranked uses strict anti-cheat — a rejected run does not update rating.
Overall vs category rating
You have separate ratings in four ranked categories:
| Category | Covers domains |
|---|---|
| Arithmetic | addition, subtraction, multiplication, division, mixed |
| Algebra | fractions, linear, quadratic, word problems |
| Powers & roots | powers, roots |
| Equations | domains mapped to this category |
Overall rating is a weighted average of categories — weight grows with games played (√games) and your adaptive domain preferences.
Leagues
Rating maps to a league with three divisions (except the top tier). Divisions climb with your rating — I is the entry band and III is closest to the next tier, so a higher Elo always means a higher division:
| League | Rating range | Divisions (low → high) |
|---|---|---|
| Novice | 0 – 899 | I, II, III |
| Solver | 900 – 1199 | I, II, III |
| Strategist | 1200 – 1599 | I, II, III |
| Mastermind | 1600 – 1999 | I, II, III |
| Grand Mastermind | 2000+ | — |
Example: rating 1050 → Solver II.
Adaptive algorithm (domain levels)
Each domain has its own level (1–max). After each series the system evaluates your answers in that domain.
Decision rules
The system needs at least 3 answers in a domain per series (MIN_SAMPLE) to change level.
| Condition | Decision |
|---|---|
| Accuracy ≥ 85% and timing OK | Level up |
| Accuracy < 60% | Level down |
| Between 60% and 85% | Hold |
| Too few answers in domain | Insufficient data |
“Timing OK” means average response time ≤ 130% of expected time for that level.
Learning zone
The system targets 60–85% correct — hard enough to learn, not enough to discourage.
Question mix per series
- Auto training: ~3 domains per series
- Quick play: 3 domains, levels from Elo rating
- Ranked: 5 domains, levels from play history
Quests
Quests award bonus XP on completion.
Daily
| Quest | Goal | Reward |
|---|---|---|
| Warm-up | 20 questions answered | 50 XP |
| Sharp eye | 15 correct answers | 60 XP |
| XP collector | 150 XP in a day | 40 XP |
Weekly
| Quest | Goal | Reward |
|---|---|---|
| Week marathon | 150 questions | 200 XP |
| Ranked warrior | 3 ranked series (ranked or quick) | 150 XP |
Daily quests reset at UTC midnight; weekly quests reset on Sunday.
Season
An active season accumulates XP from all sessions. A separate season leaderboard ranks players by XP earned in the current season — independent of Elo rating.