How to Use BaseChaser
A guide to every feature on the site. BaseChaser runs 100,000 Monte Carlo simulations daily to estimate each MLB team's playoff chances.
⚾ Today's Games & Impact Ratings
At the top of the page, you'll see every MLB game scheduled for today. Each game card shows:
- Team matchups with logos, abbreviations, and current playoff odds
- Impact rating — color-coded to show how much the game affects the playoff picture:
- HIGH — this game could swing a team's odds by 3%+
- MEDIUM — moderate impact (1-3%)
- LOW — minimal impact on playoff odds
- Live scores — if a game is in progress, the score updates
Tip: Click any team name in a game card to jump directly to that team's Deep Dive section.
📈 Odds Movement Chart
This chart shows how every team's playoff odds have changed over the season. Each line represents one team's daily odds, locked at midnight PST.
How to read it
- The Y-axis is playoff probability (0-100%)
- The X-axis is the date range from Opening Day to today
- Rising lines = teams gaining ground, falling lines = fading
Interacting with it
- Hover over any point to see the exact odds on that date
- Click "Expand" to open the full-screen Odds Explorer (see below)
- Click "Share" to generate a shareable screenshot of the chart
🗺️ Odds Explorer (Full Screen)
The Odds Explorer is a full-screen interactive chart that gives you complete control over what you see. Open it from the Odds Movement chart's "Expand" button or from the hamburger menu.
Filtering teams
- ALL / AL / NL — filter by league
- Division buttons (AL East, NL Central, etc.) — show only teams in that division
Toggling teams
Below the chart, team chips show every team in your current filter. Click a chip to toggle that team off (it will grey out with a strikethrough). Click it again to bring it back.
Compare mode
Click the "Compare" button to enter compare mode. Select exactly two teams to see a side-by-side comparison showing:
- Both teams' lines highlighted
- The delta (difference) between them at each point
Big Movers
At the top, the Big Movers section shows the 5 teams whose odds have changed the most over the last 14 days. Each shows the net change and from/to percentages.
Date range slider
Drag the handles on the date slider to zoom into a specific time period.
Tip: The Odds Explorer is great for answering questions like "When did my team's odds peak?" or "Who's been the hottest team this month?"
🦋 Butterfly Effect Simulator
This is one of BaseChaser's most unique features. It lets you pick the winners of tonight's games and see how those results would ripple across the entire league's playoff odds.
How to use it
- Click "Expand" to open the simulator
- For each of tonight's games, click the team you think will win
- Watch the odds table update in real-time as you pick winners
- The table shows every team's current odds, projected odds based on your picks, and the change
What it answers
- "If my team wins tonight, how much do their odds improve?"
- "Which other games tonight matter most for my team?"
- "What's the best-case scenario for my team tonight?"
Tip: Try picking all favorites, then switch to all underdogs — you'll see how dramatically the playoff picture can shift in a single night.
📊 Full Standings Table
The standings table shows every team ranked by playoff odds, with detailed stats:
- Record — wins, losses, win percentage
- Playoff % — overall probability of making the postseason
- Change — how much the odds shifted since your last visit (green = up, red = down)
- Div % — probability of winning their division (seeds 1-3)
- Bye % — probability of earning a first-round bye (seeds 1-2)
- WC % — probability of making the playoffs via wild card (seeds 4-6)
- Streak — current win/loss streak
Filtering
Use the filter buttons above the table to view by league (AL/NL) or by division.
Tip: Click any team name in the standings to jump to their Deep Dive.
🔍 Team Deep Dive
Select any team from the dropdown to see a comprehensive breakdown of their playoff picture:
What's included
- Headline odds — big number showing current playoff probability
- Seed probabilities — chances of landing each playoff seed (1-12)
- What-If table — if they finish with X wins, what are their playoff odds?
- Tonight's scenarios — how each game tonight affects this team
- Tomorrow's scenarios — preview of tomorrow's impact
- Schedule difficulty — how tough their remaining schedule is
- Hardest remaining series — their toughest upcoming opponents by Elo rating
- Magic/tragic numbers — wins needed to clinch or losses to be eliminated
- Projected final record
Tip: The "Tonight's Scenarios" section is especially useful for knowing which games to root for if you're a fan of that team.
🫧 Bubble Watch
Bubble Watch highlights teams on the playoff bubble — those with odds between 15% and 85% who haven't clinched or been eliminated. These are the teams whose fates are most uncertain.
- Teams are sorted by how close they are to the 50/50 line
- Each card shows odds, record, change since yesterday, and a visual bar
- Early in the season most teams are on the bubble; late in the season only a handful remain
📤 Sharing & Screenshots
BaseChaser has built-in sharing features:
- Share button (header) — copies the page URL to your clipboard, or opens the native share sheet on mobile
- Chart share — the "Share" button on the Odds Movement chart generates a screenshot image with a team legend and BaseChaser branding, ready to post on social media
🌙 Dark Mode
Click the "🌙 Dark" button in the header (or in the hamburger menu) to switch between light and dark mode. Your preference is saved and remembered on your next visit.