About Sports Lobby

What this site is

Sports Lobby is a small set of browser tools for people who run competitions or keep score: brackets, schedules, league tables and per-sport calculators. There are no accounts and no server-side processing. Every tool is JavaScript running on your device, and nothing you enter is transmitted or stored. The pages show a correct worked example even with JavaScript switched off.

None of the tools use data feeds. They know only what you type, so there are no live scores, no rankings and no predictions. That keeps them simple, private and checkable.

Organising a competition

League manager

Fixtures come from the circle method below. The table applies the points and tiebreakers each governing body publishes for league or group play: the Premier League's order for soccer (points, goal difference, goals scored, head-to-head), FIBA Appendix D for basketball (2 for a win, 1 for a loss, 0 for a forfeit, head-to-head first), the FIVB competition regulations for volleyball (wins, then 3-2-1-0 match points, then set ratio) and the NHL procedure for hockey (2 for a win, 1 for an overtime or shootout loss). Head-to-head criteria use only the games among the teams still level, recomputed as the group shrinks. The league is stored in the link's fragment, compressed with deflate, and never sent to a server. Limits: no volleyball points ratio (only set scores are entered), no split between overtime and shootout wins, no points deductions, and no playoff or draw-of-lots step: teams level on everything share the position. Sources are linked on the tool page.

Tournament bracket maker

Brackets are rounded up to the next power of two, and the empty lines become byes. Positions follow the standard seed order, built by replacing each seed s with the pair (s, 2k + 1 − s) at every doubling, so that first-round seeds always add up to the bracket size plus one and the top seeds are spread into different sections. Byes therefore fall to the top seeds. A random draw is a Fisher-Yates shuffle driven by a numbered seed (mulberry32), so the same list and draw number always give the same draw. Double elimination feeds winners’ bracket losers into the losers’ bracket in reverse (then half-swapped) order to delay rematches, and replays the grand final if the losers’ side wins it (optional). Swiss pairs the top half against the bottom half in round 1, then by points, avoiding rematches, with the bye going to the lowest-placed player without one; standings use points then Buchholz. Limits: no re-seeding between rounds, no rules for separating teams from the same club, and Swiss pairing is the simple by-standing method, not the FIDE Dutch system with colour allocation. The printable brackets use the same engine.

Round-robin schedule generator

The circle (polygon) method: one team fixed, the others rotating one place per round, with a placeholder added for an odd number of teams so each team rests once. Home and away totals are kept within one game of each other; a double round robin mirrors the first half with venues swapped. Limits: it balances totals, not streaks, so a team can have several home games in a row, and it knows nothing about dates, venues or other constraints.

Tables and races

League standings calculator

Points are wins, draws and losses multiplied by the chosen values. Winning percentage is (W + ½D) ÷ P, the convention the NFL uses for ties. Games behind is ((W_leader − W) + (L − L_leader)) ÷ 2. Level teams are separated by difference, then scored, then wins. Limits: no head-to-head tiebreakers (which many leagues apply first), no points deductions, bonus points or overtime-loss points.

Magic number calculator

Magic number = G + 1 − W_leader − L_rival, with G the season length, or G − W − L if the leader is known to hold the tiebreaker. The leader's clinch number is its largest magic number against any rival, and each rival's elimination number is the leader's magic number against it. Limits: exact for first place within the teams you enter; only a guide for wild-card or multi-team playoff races; assumes no tied games.

Scoring

Bowling score calculator

Standard ten-pin scoring: an open frame scores its pins, a spare scores 10 plus the next ball, a strike 10 plus the next two, and the tenth frame gives fill balls after a strike or spare. Input is validated ball by ball against the pins standing. Limits: not for candlepin, duckpin or five-pin, and not the newer "current frame" scoring system; no league handicaps.

Golf handicap calculator

The World Handicap System, used by the USGA, The R&A and most national associations since 2020. Score differential = (113 ÷ Slope) × (adjusted gross − Course Rating − PCC); Handicap Index = the average of the lowest 8 of the latest 20 differentials, with the published table for fewer scores; Course Handicap = Index × Slope ÷ 113 + (Course Rating − Par). Limits: it cannot apply the soft and hard caps, exceptional-score reductions, 9-hole score handling or the daily playing conditions calculation unless you enter PCC yourself. It estimates an index; only an authorised association issues an official one.

Batting average, OBP, SLG and ERA calculator

The standard definitions: AVG = H ÷ AB, OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF), SLG = total bases ÷ AB, OPS = OBP + SLG, BABIP = (H − HR) ÷ (AB − SO − HR + SF), ERA = 9 × ER ÷ IP (or 7 or 6 for shorter games), WHIP = (BB + H) ÷ IP. Innings in box-score notation (6.1 = 6⅓) are converted to outs first. Limits: no park or league adjustment, and rates over small samples are noisy.

Odds

Odds converter and implied probability

Pure arithmetic: every format is converted through decimal odds, and implied probability is 1 ÷ decimal odds. The margin in a set of prices is the amount by which their implied probabilities exceed 100%, and the "margin removed" figures divide each implied probability by the total. Limits: proportional margin removal is one of several methods; others (Shin, power) give different results for long shots. The page is educational: it does not recommend or promote betting and has no links to betting services.

Who makes it

Sports Lobby is a small independent site run by one person. It is not affiliated with any league, governing body, app or retailer. Rules are taken from the governing bodies' own published documents, linked where they are used, and each tool page carries a worked example so you do not have to take the arithmetic on trust.

Corrections

If something here is wrong, please say so. The rules and formulas are stated on every page so they can be checked, and a mistake in a rule will be fixed rather than argued with.