The Rama[1] cites the minhag that it is proper to blow the shofar on the right side of the mouth. (Sephardim also seem to have adopted this minhag.[2]) His reason is that the Satan is on the right side, and through the shofar blowing, we counter and confuse him.[3] (The connection between the shofar and the Satan is a major theme with various ramifications, and we should not belittle its importance, as shofar is a mitzva whose whole nature revolves around hidden messages.) The Bi’ur Halacha[4] further notes that when Gideon’s men were blowing the shofar at the time of war, they held the shofars in their right hands.
That being said, the poskim, starting with the Rama, present the idea of blowing on one’s right side as a preference, not as a requirement. Let us investigate different factors that may influence the matter.
Some of the people who are able to blow the shofar only on the left side are left-handed. The Magen Avraham[5] says that a left-handed person should blow on the left side. He bases his ruling on the explanation of the minhag that the left side of a right-handed person does not need the shofar’s help because tefillin are donned on his left arm. The Magen Avraham therefore suggests that a left-handed person who puts tefillin on his right arm should blow on the left. However, the Aruch HaShulchan[6] counters that we are not interested in where the ba’al tokeiah puts his personal tefillin, but rather the practice of the majority of the congregation, who are presumably right-handed. Furthermore, most poskim maintain that even a left-handed person should blow on the right side.[7] On the other hand, the Levush[8] claims that according to Kabbala, it is better for all to blow on the left side.[9] Although the “pro-left” opinions are not accepted, they further weaken our resolve to insist that the ba’al tokei’ah blow on the right side of his mouth.
When it comes to priorities in picking a ba’al tokei’ah, the Maharam Shick[10] gives precedence to one who is learned and God-fearing but can blow only on the left side of his mouth over a relatively ignorant or less scrupulously religious person who blows on the right side. This parallels the general guidelines regarding those who lead services on Rosh Hashana.[11] The Yalkut Yosef[12] concurs.
The quality of the blowing is also more important than the issue of blowing on the right side. Although a congregation will usually fulfill its mitzva by listening to one who struggles through the teki’ot with mistakes and delays, this situation entails several regrettable elements: 1) It is not an honorable way for the mitzva to be fulfilled. 2) Some people, especially those who are not able to be present for the entire period of the shofar blowing, may not hear enough proper blasts to fulfill the mitzva. 3) Some congregants are so taken by the drama of whether and when the ba’al tokei’ah will make it through his duties that they neglect to concentrate on the essential concerns of the day (including repentance and accepting HaShem’s dominion). 4) Some people may begin to talk, even lashon hara, and act in an undignified manner.
The Maharam Shick[13] invokes another factor, which cannot be overemphasized. All such decisions should be made with sensitivity and with a strong desire to avoid discord. This is always appropriate, but it is certainly crucial on the High Holy Days. Another general consideration is that one who leads the services should be acceptable in the eyes of the congregation.[14]
Many of the factors we have mentioned do not have clear cut definitions. How proficient is proficient? How righteous is righteous? How likely does discord have to be in order to be a consideration? Making such a decision is among the difficult tasks that earn a rabbi or a gabbai his keep.