While it has never been easier to find out how much your cards are worth, selling them for that price can still be harder than you’d expect.
Mantel, a social-media platform for the hobby, is hoping to eliminate some of that friction with its new SLAM Score — a tool that attempts to quantify how liquid and desirable a card is at the moment.
Shorthand for Secondary Liquidity & Momentum, Mantel’s SLAM Score originated as an idea from content and community marketing director Mike Metzler. A longtime collector, Metzler has often found himself met with many of the same issues that plague hobbyists hoping to sell cards at local shops or shows.
For dealers, the preference is to bake in profit by buying at a percentage much lower than the current market value. Dealers will also often decline to purchase cards that might not have many buyers, and instead focus on only popular cards of popular players.
Scored from 0 to 100, a higher SLAM Score is given to cards that are highly liquid and often have little price volatility. Lower scores can still be great cards, but might be harder to sell to the average collector.
“The idea behind this was pretty simple: How close is the card to 100% cold, hard cash,” Metzler told cllct. “If it’s 100, you should be able to walk into any show and say this has sold 150 times at this specific price over the last 30 days. You’ll be able to sell this. I don’t need to take 70% comps.”
For Mantel, the goal was to solve a common problem impacting collectors by adding a valuable data point to what has likely been an oversimplified process. For many buyers and sellers, the most recent sale — or handful of sales — are all that matter.
Additional variables, like total sales volume, price volatility and sales velocity should all likely play a larger part in the process, and SLAM attempts to capture that with a normalized score.
“I think the average data point that people are using in the card space is comps, and comps are only so helpful, right?” Mantel CEO Evan Parker told cllct. “What something sold for yesterday or 29 days ago is not necessarily what that thing is worth.”
Launched Wednesday, the SLAM Score can currently be found when collectors are searching for cards on the platform’s marketplace, which pulls listings from platforms including eBay and Fanatics Collect. Alongside the SLAM Score, hobbyists can see the card’s grade, the population report and the most recent sale.
Mantel pulls data from a number of partnered sources, including marketplaces and data tools, and hopes the number of cards with SLAM Scores will quickly expand as they hit the secondary market.
According to Parker, SLAM is the newest addition to a growing suite of free tools the platform has created to make collecting easier for hobbyists. Launched in December 2024, the platform doesn’t plan to compete with other hobby-related apps, which are largely made up of card scanners and data tools.
Instead, Mantel has targeted other social platforms, including Reddit, X and Instagram, which are currently among the go-tos for hobbyists. Mantel, however, can offer specialized tools for a very specific community those platforms don’t cater to.
Mantel also launched a new “Want It” tool alongside the SLAM Score update Wednesday, joining unique features such as the platform’s Mantlepiece — an area where hobbyists show off items in their collection they are most proud of.
“We need to do things people are going to pay attention to,” Parker said. “People are going to want to download Mantel because a lot of our time and energy is put on big things that nobody else is doing. It’s not what we can take from somebody else and add to Mantel, but can we create something new that will make Mantel stand out from our competition?”
“I want to build tools that champion the buyer,” Metzler added. “We educate them and we help remove that chance that they’re going to get scammed or taken advantage of. We’re pretty passionate about that.”
You can read more about Mantel and its new SLAM Score on Yahoo Collectibles.
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Ben Burrows is a reporter and editor for cllct, the premier company for collectible culture. He was previously the collectibles editor at Sports Illustrated. You can follow him on X and Instagram @benmburrows.