Game used items are any items used or worn during the course of a sporting event. Each individual item is unique, and the value of each one is driven by the events it is associated with paired with scarcity. Let's say you acquired Jose Altuve's game used jersey from October 19, 2019. While there may be many Altuve jerseys out there, and several from the same postseason, there is only ONE jersey that was worn for his iconic walk-off home run to send the Astros to the World Series. This same thought process applies to even the most common items - game used baseballs. While hundreds are used every game, if you have Jose Altuve's Home Run ball from July 28, 2019, you not only have a rare home run ball, but you also have his 1,500th hit. That makes the item both historic AND rare, thus driving the price up.

Game used items are items that can conclusively be determined to have been used in the course of playing a game, while team issued items are those that were assigned to a player and may or may not have seen use in a game. An item that is authenticated as Team Issued may still have been used in a game.

There are many different forms of authentication, each with varying levels of reliability. MLB Authentication - often considered the gold standard, MLB authenticated items are witnessed and authenticated on the spot at the moment of the event. Even still, authenticators are humans, and mistakes have been known to happen. While rare, this happens most often with the details of game used baseballs, as they can sometimes be removed from play quickly. 3rd Party Authentication - PSA/DNA, Mears, Grey Flannel, Dave Miedema LOAs. All of these are essentially letters of opinion. They compare player specific characteristics along with visible signs of use to form an opinion as to whether a particular item is likely to have been used by a particular player. Each 3rd party has varying levels of reputability - I strongly encourage you to do your research and form your own opinions. Hi-Resolution photo matching services. Think of this as fingerprinting your memorabilia. Just like a fingerprint, each game used item will have unique identifying characteristics. Unique marks, stains, thread pulls, letter placement relative to fixed points, and even holes in the mesh of a uniform can be used to create a "fingerprint" of a jersey. Letters of Provenance - These are letters from a reputable source detailing the chain of custody of a particular item. These are often from friends, family, team employees, or even the player themselves. They can range from highly detailed to a player simply inscribing "Game Used" under their signature on a particular item. While there may be other forms of authentication out there, these are among the most prominent and respected within the baseball segment.

When it comes to MLB Authentication, an item can only be deemed as game used if it never leaves the sight of the authenticator. For an easy to follow example, consider the jersey of a starting pitcher. When the starter is lifted for a reliever late in the game, they often go to the clubhouse to receive treatment and change out of their uniform. If there is no authenticator in the clubhouse, their uniform becomes laundry. At the end of the season, many uniforms may be hanging in a player's locker that were used during the season that were not authenticated after use. The MLB authentication program has grown leaps and bounds over the years, and different teams use different methods to authenticate uniforms. This has reduced the number of game used items that slip through the cracks, but there are still many items that this applies to including bats, gloves, hats, pants.

Most MLB teams have an "Authentics" store inside the stadium that deals in MLB authenticated items. During the season, this is a great place to purchase items. MLB Auctions are another great source of game used and team issued memorabilia. Auction Houses. Private sales. And of course, right here at The Astros Locker!

Generally speaking, these are the factors that determine value: The player who used it. This seems obvious, but a superstar jersey worn just once is worth more than a jersey worn all year by the last man on the bench. The season it was used - Rookie, MVP, Championship, Cy Young, etc. The play or game an item was authenticated to - a bat used to hit a home run will be worth more than a bat broken while hitting into a double play. Scarcity. Some players retain more of their items than others, creating more demand. Other players may have less supply due to their time in the sport or with a particular team. The team a player plays for. Love it or hate it, a Yankees jersey will be worth more than a Marlins jersey for the same player. I'm looking at you, Giancarlo. As always, an item is worth what someone is willing to pay for it.

This is a complicated answer with lots of opinions. Some people love an autograph on their game used items, while others prefer them to look just as they did when they were removed from play. There is no consensus. When deciding whether or not to get an item autographed, my advice is to only get it signed if you plan to keep it in your collection forever. Once that autograph is added, for better or worse, you have eliminated some potential buyers who consider themselves purists. My personal opinion is that a rare or highly priced autograph on a game used item will seldom hurt the value of that item.