This potentially crucial question – if a professional baseball player were to decide to keep Shabbat, could he play on Shabbat? – was not asked by or on behalf of a player. If he were to ask, it would be necessary to analyze all aspects of the question, certainly including the issues of going to one’s job even if one does not need to do melacha,[1] being paid for work on Shabbat, uvdin d’chol,[2] the spirit of Shabbat, and impact on the public. We would have to keep in mind the likelihood that he would have to give up a very profitable career and the possibility that a stringent ruling would hold him back from mitzva observance. We will not do that in this response. As the question was asked by a curious sports fan, we will take the hopefully enlightening (and entertaining) opportunity to apply some intricacies of the laws of Shabbat to some intricacies of baseball in a more theoretical manner.
All Major League stadiums are fully enclosed, making them reshuyot hayachid[3] despite the masses of people who assemble there.[4] Thus, carrying, hitting, and throwing in the stadium are not chillul Shabbat. While there are Rabbinic restrictions on carrying even in a reshut hayachid without an eiruv,[5] they only apply when carrying between areas owned by different people or groups.[6] An entire stadium is owned by one person or group, so this is not a problem.
What if one hits a home run, in which case (in certain parks) the ball can go from an enclosed to an unenclosed area? A disciplined hitter will not intend to hit the ball out of the stadium, beyond the playing field wall. Therefore, even if a player hit a home run that left the entire stadium, it would be a davar sh’eino mitkavein (an unplanned, uncertain violation of Shabbat). One does not have to be concerned from the outset that his ostensibly permitted action (hitting the ball hard) may unintentionally turn into a Shabbat violation.[7]
Often, hitters “dig in” at the batter’s box by using their cleats to make a small ditch to help them push off when swinging. This is a form of choresh (plowing) or boneh (building)[8] that is done directly and purposely to improve the ground for one’s purposes, and it is a Torah-level violation.[9] (See the Mishna Berura’s[10] objection to playing on the ground, which does not seem to apply to baseball.)
Sliding on the base paths dirties a player’s uniform. The gemara[11] says that one who shakes out his clothes to remove dew (according to Tosafot) or dirt (according to Rashi) violates a Torah prohibition. The gemara continues that this applies only to new, black clothes, which one is careful to keep clean. The Rama[12] cites opinions that one may not shake out any article of clothing on which he is not willing to tolerate that level of dirt. While the matter is more complex than we can address here, the Bi’ur Halacha[13] rules stringently on the matter when one does not only shake out the clothing, but also performs an action of cleaning on the place of the dirt. Therefore, it is at least preferable to do no more than lightly shake off the top layer of dirt, leaving whatever is partially imbedded in the fabric.
When playing the outfield, is there a problem of cutting or uprooting the grass (a question not applicable to stadiums with artificial turf)? In general, one is allowed to walk on grass because even if he were to cut some blades, it is a davar sh’eino mitkaven.[14] However, the Mishna Berura[15] points out that if one runs on tall grass, it is a p’sik reishei (a certainty that one will inadvertently perform the prohibition), which is forbidden. Although stadiums have short grass, it is possible that with cleats, the matter is a p’sik reishei, and this respondent lacks the technical expertise to rule on the matter.
The Shulchan Aruch[16] rules that balls are muktzeh because they do not have a serious use that would make them utensils. The Rama says balls are not muktzeh because they are set aside for the purpose of playing, which he considers sufficient. Therefore, balls are not muktzeh for Ashkenazim; Sephardim are divided on the matter.[17]
In summary, by taking proper precautions, one can solve most, if not all, of the technical halachic issues of playing baseball on Shabbat, while certain halachic and certainly spiritual issues would remain (including some that we have not mentioned).