This is no secret: Front offices are smarter than ever and, believe it or not, make fewer mistakes than ever. Fewer big mistakes, at least. Consider some of the players traded as prospects last decade (from 2010-19): Yordan Alvarez, Zack Wheeler, Max Fried, Trea Turner, Luis Castillo, Sandy Alcantara, Zac Gallen, Dansby Swanson, Fernando Tatis Jr., Dylan Cease, Anthony Rizzo, Patrick Corbin, Lucas Giolito, Willy Adames, Jesus Luzardo, Gleyber Torres.That's six of the top 12 pitchers this decade via WAR and five of the top 30 position players. Some of the deals worked out for the teams trading away the prospect: The Cubs won a World Series with Aroldis Chapman (traded for Torres) and the Nationals won a World Series with Adam Eaton (traded for Giolito) -- but most did not.We're halfway through the 2020s and we haven't seen nearly as many of those kinds of trades (so far, anyway). Top prospects are the gold currency of MLB, to be parted with only in acts of desperation. But mistakes have still been made: bad trades, bad signings, bad decisions in the playoffs. Stealing an idea from ESPN NFL writer Bill Barnwell, we're going to dig up the worst decision each team has made through these past five years, evaluating the outcome and not the process.We'll start with the least damaging of the moves and end with the biggest mistake so far of the 2020s.Jump to a team:American LeagueATH | BAL | BOS | CHW | CLEDET | HOU | KC | LAA | MINNYY | | SEA | TB | TEX | TORNational LeagueARI | ATL | CHC | CIN | COL LAD | MIA | MIL | NYM | PHIPIT | SD | SF | STL | WSH