Catcher throws to first on a bases empty ball four.

[BretMan]

There's preventive officiating and there's over-officiating (I guess plain old-fashioned officiating lies somewhere in the middle). Giving a warning here strikes me as over-officiating. The catcher isn't breaking any rule or pushing any boundary of unfair play.

Heck, any player at any position at any point of the game might potentially commit an unsportsmanlike act. That's a lot of potential warnings!

Another thing to keep in mind is that, under FED rules, on a base on balls the batter-runner is not exempt from liability from being tagged out if he overruns first base. Maybe the defense is trying to exploit this odd glitch in the rules and catch the B/R napping if he crosses the bag.

Have I ever seen this? Maybe a couple of times, if that. Certainly not enough times to say it's a common strategy or growing trend.

Do I ignore this? I would ignore issuing a warning, but I wouldn't ignore the ball or the B/R since there is a potential tag play in the offering.