This article answers the simple question of how JJ Spaun was priced to win the 2024 U.S. Open and shows how to convert those market quotes into implied probabilities you can compare to your own model. The focus is evidence based: archived pre event aggregator snapshots and a standard conversion method are used so you can check the same pages yourself. If you want a concise headline: Spaun was priced as a longshot in public pre event markets, and converting representative quotes like 150/1 (shown as +15000 in American odds) yields an implied chance well under one percent. The article walks through the math, points to the archived boards used as sources, highlights common pitfalls, and ends with a short checklist so you can reproduce the checks independently.

Archived aggregator snapshots around June 12 to June 13, 2024 listed JJ Spaun as a longshot near 150/1.

A +15000 American quote converts to roughly a 0.66 percent implied win probability using the standard formula.

Longer quoted lines like +30000 imply approximately half that chance, roughly 0.33 percent.

Quick answer: How JJ Spaun was priced to win the U.S. Open

Short answer: archived aggregator snapshots around June 12 to June 13, 2024 listed JJ Spaun as a deep longshot, with typical prices shown near 150/1 (often displayed as +15000 in American odds) and some books or snapshots moving into longer five digit American quotes; that pre event level converts to an implied chance well under 1 percent for an outright win, and the markets treated him outside the favorites tier, which you can verify on archived aggregator pages such as the OddsChecker archive OddsChecker archive.

Put simply, a 150/1 listing and an American quote like +15000 are two ways the same market view was shown, and applying the standard implied probability conversion yields an approximate 0.66 percent win probability for that quote; longer five digit quotes such as +30000 imply roughly half that probability in the same math. The snapshot evidence that Spaun sat at longshot prices is captured on multiple archived boards from the week before the event, which is why most pre event summaries and aggregator pages grouped him away from top contenders.

Quick conversion checklist referencing the Investopedia formula

Reference page
Fractional to American
American to implied
Example numbers

Use the linked Investopedia page for the formula

Short summary

For readers who want a headline: archived aggregator boards around June 12 to June 13, 2024 showed JJ Spaun at about 150/1 or at long American odds in five digits, which converts into a sub 1 percent implied chance before play began; the OddsChecker and VegasInsider archived snapshots capture that market placement VegasInsider archive.

What the quoted numbers mean in plain terms

Seeing 150/1 tells you that the market viewed Spaun as a low probability outcome, and the equivalent American quote +15000 reduces that fractional view to a simple percent using the standard formula. When you plug +15000 into the implied probability conversion, you get an approximate 0.66 percent chance to win, which is tiny compared with prices for the favorites; the Investopedia page on implied probability explains the conversion approach used here Investopedia implied probability.

How to read odds formats and convert them to implied probability

Fractional odds versus American odds

Odds appear in several formats; fractional odds like 150/1 are common in some markets and are read as the net return relative to stake, while American odds express the same idea as a signed number, where plus signs indicate how much a 100 unit stake would win. Converting between fractional and American is straightforward for large longshot fractions: 150/1 becomes +15000 by multiplying the fraction by 100 and adding the plus sign for presentation, and that same quote can be used in the implied probability formula that bookmakers and analysts use to back out market implied chances.

The standard conversion formula and a one line example

For positive American odds the standard implied probability formula is 100 divided by (American odds plus 100), converted to percent; using that rule with +15000 the calculation is 100 / (15000 + 100), which produces roughly 0.66 percent. The Investopedia explanation lays out that formula and shows the arithmetic steps readers can reuse, and the Action Network provides a complementary primer on how implied probability works in practice for comparing market lines Investopedia implied probability.

If you are not comfortable with the arithmetic, any simple calculator or spreadsheet cell that implements 100/(odds+100) for positive American odds will reproduce the same percentage, and the same conversion applies if you first convert fractional odds into an equivalent American number before applying the formula.

Pre tournament snapshots: What archived boards showed for JJ Spaun

Which aggregator pages captured Spaun's price

Archived aggregator boards captured the pre event market for the 2024 U.S. Open and show Spaun listed well down the board; an Internet Archive snapshot of OddsChecker from June 12, 2024 is one of the clearest pre event captures showing longshot listings around 150/1 for lower ranked names OddsChecker archive. Related contemporary coverage can be found in reporting such as the New York Times NYTimes piece.

Variation across sources and timing

A separate archived snapshot from VegasInsider dated June 13, 2024 shows similar longshot placements for Spaun, but snapshots differ by timing and by which sportsbooks each aggregator captured, meaning some pages recorded five digit American quotes while others listed the fractional 150/1 form; the VegasInsider archive provides a contemporaneous board snapshot for comparison VegasInsider archive.

Funded Plays Challenges

Run the conversion

Beyond aggregator boards, market overview pages from outlets like TheLines placed Spaun outside the principal favorites tier in their pre event previews, which aligns with the archived price placement across the aggregator snapshots and preview articles TheLines odds overview, and the PGA Tour betting profile also offers related market commentary PGA Tour betting profile.

Because aggregator pages pull from multiple books, you will sometimes see slightly different displays of the same market: a fractional 150/1 on one board alongside a +15000 or longer American quote on another. Those differences are typically presentation and timing effects rather than substantive contradictions about where the market placed a player overall.

Exact conversion examples and quick math you can reuse

Convert +15000 to implied probability step by step

Step 1: Recognize the American quote as positive, meaning use the positive-odds formula. Step 2: Apply the formula 100 / (odds + 100). For +15000 this is 100 / (15000 + 100) which equals 100 / 15100.

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Step 3: Compute the numeric result. 100 divided by 15100 is approximately 0.0066225, which as a percentage is roughly 0.66 percent. This is the implied win probability the market expressed for a +15000 quote, and the Investopedia resource used here documents this calculation and the reasoning behind the formula Investopedia implied probability.

Convert +30000 and show the difference

For a +30000 quote the same formula gives 100 / (30000 + 100) = 100 / 30100, which equals approximately 0.003322, or about 0.33 percent. That numeric example shows how a doubling of the American odds roughly halves the implied probability in this range of longshot pricing.

When you compare +15000 and +30000 directly, the implied chance moves from roughly 0.66 percent to about 0.33 percent, illustrating how even large numeric changes in the odds translate into modest absolute changes in probability when both are small numbers.

A brief rounding note: public boards may round displayed odds and small probabilities differently, so small differences in the third decimal place are not meaningful for interpretation; the conversion method nonetheless gives a consistent apples to apples view for comparing quotes across boards.

What those market implied probabilities tell us about Spaun's chances

Interpreting probabilities under 1 percent

An implied win probability near 0.66 percent is consistent with a longshot designation: it says the market assigned Spaun a small but nonzero chance of outright victory, and that placement is materially different from the percentages attached to favorites, which typically sum to much larger individual probabilities on pre event boards; TheLines' pre event overview grouped Spaun away from the top contenders in that same market context TheLines odds overview.

Viewed another way, a 0.66 percent chance means that if an identical event were repeated many times under the market's assumptions, Spaun would be expected to win roughly six to seven times out of one thousand such repetitions, which is why markets and preview pages treated longshot names differently from the primary favorites.

Verify archived quotes and convert them yourself

Check the archived boards and run the same conversion on any quoted American odds to see how market implied probabilities compare across players.

Run the conversion

Whether any single longshot price represented 'value' depends on a reader's independent model and assumptions; the market-implied numbers are a reference point, and the methodology above provides a consistent way to compare your own estimate to the consensus reflected in the odds.

How Spaun's pricing compared to other contenders in previews and boards

Where Spaun sat on major odds boards

Preview pages and large odds overviews listed Spaun outside the primary favorites tier prior to play. Market commentary around June 11 and 12, 2024 identified a handful of favorites and contenders who drew the majority of market attention, while Spaun appeared further down boards captured in the archived snapshots; DraftKings Nation's preview reflects the usual distinction between top listed names and longshot entries in pre event coverage DraftKings Nation preview, and additional coverage is available from Front Office Sports Front Office Sports.

Short comparison to the top listed favorites

Being listed at about 150/1 puts a player in a different market rank than top favorites, whose implied probabilities are typically many times higher and who attract primary market attention and depth of liquidity. That qualitative gap explains why boards and preview articles separate the “favorites tier” from the longshot group when summarizing the pre event market.

If you want to inspect exact favorite odds and the full leaderboard, the archived aggregator pages and pre event previews linked earlier in the article are the right places to check for the complete raw boards rather than relying on summary commentary alone.

Minimalist 2D vector calculator and notepad in Funded Plays colors showing an implied probability layout for quick reference ideal for us open tennis odds content

Limitations of archived odds and live updates during the event

Why exact intratournament pricing can be hard to reconstruct

Public archives capture snapshots at particular times, but comprehensive, timestamped intratournament records for every player and book are rarely publicly archived in full granularity; that means reconstructing exact intratournament price paths for a single player like Spaun can be limited by available captures and by which books an aggregator saved at a given moment, as noted in market coverage summaries TheLines odds overview.

What odds was JJ Spaun to win the U.S. Open?

Pre event archived aggregator snapshots from June 12 to June 13, 2024 listed JJ Spaun as a longshot around 150/1, which converts to roughly a 0.66 percent implied win probability for a +15000 quote; some snapshots recorded longer five digit American odds that imply lower probabilities.

Some outlets provided live odds feeds or periodic updates during rounds, and those can show intra event movement, but publicly archived aggregator snapshots are typically the best available evidence for pre event placement and are limited when it comes to dense intratournament tick data.

If you plan a detailed market reconstruction, a practical step is to save timestamped page captures during play or to use a commercial odds data service that records frequent ticks, because public archives often leave gaps in intratournament coverage (see how Funded Plays evaluations work here).

Common interpretation mistakes and how to avoid them

Rounding and quoting confusion

A common error is to treat the displayed fractional or American number as exact without allowing for rounding conventions; small posted differences in a longshot's displayed odds can translate into tiny percentage differences, so double check the underlying number and apply the conversion formula consistently to avoid rounding mistakes, as general guidance on implied probability explains Investopedia implied probability.

Misreading implied probability as a forecast guarantee

Another frequent mistake is to interpret implied probability as a promise about what will happen rather than as the market's aggregated chance under its own pricing and margin structure. Implied probability is a market snapshot, not a guarantee, and treating it as a forecast rather than a reference can lead to poor decisions if you do not compare it to an independent model.

Finally, remember to account for bookmaker margin and the fact that summed implied probabilities across a full board will normally exceed 100 percent because books include an overround; that margin affects interpretation of any single entry's displayed implied chance.

Practical takeaway and how to reproduce these checks yourself

Step by step checklist

1) Find an archived board such as the OddsChecker or VegasInsider snapshot for the relevant date. 2) Note the player's listed odds, either fractional or American. 3) If needed, convert fractional odds to American form. 4) Apply the implied probability formula 100 / (odds + 100) for positive American odds. 5) Compare that result to favorite probabilities and to your own model to assess value. The archived OddsChecker and VegasInsider pages used here are convenient starting points for step 1 OddsChecker archive, and related guidance is available on the Funded Plays blog Funded Plays blog.

Where to find the referenced archived pages

The Internet Archive captures of OddsChecker and VegasInsider dated June 12 and June 13, 2024 are the two primary pre event evidence points cited in this article, and the Investopedia page gives the conversion method to reproduce the math consistently; you can revisit those pages to check raw leaderboard listings and to repeat the calculations described above VegasInsider archive.

Bottom line: archived pre event markets listed JJ Spaun as a longshot near 150/1 in several publicly archived snapshots, which converts to roughly a 0.66 percent implied win probability and places him well outside the favorites tier in market overviews. Use the checklist above to reproduce these checks yourself. For more on the site, visit the Funded Plays homepage Funded Plays homepage.

How do I convert American odds to implied probability?

For positive American odds use 100 divided by (odds plus 100) and multiply by 100 to get the percent; for example, +15000 gives about 0.66 percent.

Were Spaun's odds the same across all books?

No, quotes varied by sportsbook and timing; archived aggregator snapshots show typical listings near 150/1 but some boards displayed longer five digit American quotes.

Does a 0.66 percent implied chance mean Spaun could not win?

No. An implied probability is a market estimate, not a guarantee; longshot probabilities are small but not zero and outcomes can differ from market odds.

Use the archived pages and the conversion checklist to confirm the numbers for yourself. Market implied probabilities are a neutral reference point; whether a given longshot price is good value depends on your own model and assumptions. If you plan to analyze markets regularly, consider saving timestamped captures during play and keeping a simple calculator or spreadsheet that implements the conversion formula for quick checks.