Responsa for Bava Batra 84:6

אמר רב נחמן אמר רבה בר אבוה לומר שנוטל בשבח המגיע לכתפים בשדה שאינה עשויה ליטע כשדה העשויה ליטע:

Rabina said: In both cases [Samuel is speaking] of a partner who takes possession of the whole [of the joint field], but still there is no contradiction, because in the one case he speaks of a field which has to be divided [if either partner demands]<span class="x" onmousemove="('comment',' I.e., a field which allows of four cubits square being assigned to each. Possession of such a field confers hazakah since, as there is room for both, one partner is not likely to allow the other to occupy the whole for several years running. ');">¹¹</span> and in the other of a field which has not to be divided [if either partner objects].<span class="x" onmousemove="('comment',' I.e., a plot too small to allow of four cubits being assigned to each partner. In this case it would be natural for each partner to work the whole plot several years running, and therefore possession of the whole does not constitute a title of ownership. ');">¹²</span>

Maharach Or Zarua Responsa