The large 'beefsteak' types are most susceptible to developing irregularly shaped fruit since by definition a beefsteak contains more than six locules. With two locules, cherry and plum or pear types (the so-called processing tomatoes) are far less likely to produce "funky looking" 'maters. Commercial cultivars (F1 hybrids for the majority) are also more uniform in shape, since they contain between four and six locules. Catharine/Atlanta, zone 7b