A poet's choice of rhythmic patterns is affected by three factors: a universal set of metrical constraints, common to all languages; the metrical grammar and lexical structure of the poet's own language; and the poet's personal style. The first aim of this paper is to analyse how these three factors influence the frequency of different stress patterns in the customary metre of Ausiàs March (1400-1459): the decasyllable with caesura a minore (4+6 syllables). The second aim is to compare March's schemes of stress with the patterns used by Vicent Andrés Estellés (1924-1993) in his alexandrines in the 1971 book Llibre de meravelles (Book of Wonders). The comparative analysis shows that the same metrical constraints operate in both authors and that their weight is equivalent. This equivalence can be seen first in the similarity of their arrangement of patterns in terms of frequency, which shows a clear preference for models that are rhythmically better; and second in the similarity of the proportions of their use of different schemes. The twofold coincidence indicates that March and Estellés, in spite of the vast distance in time between them, share the same metrical grammar. All that separates them is March's slight inclination toward patterns of binary rhythm compared to Estellés's preference for ternary rhythm. This difference, which is independent of the metre used by the authors, must be attributed to their stylistic preferences.