As mentioned in earlier posts, English has a regular––and productive––alternation of the position of stress in verb/noun pairs, e. g., combát vs. cómbat, defáult vs. défault, procéed vs. próceeds, etc. In each such pair, the verb has stress on a non-initial syllable, whereas the noun has it on the initial.
This contrast extends beyond dissyllabic words to embrace verb/noun pairs consisting of more than two syllables, e. g., envélop vs. énvelope, interchánge vs. ínterchange, reprimánd vs. réprimand, etc. Even though in some of these cases the stress need not contrast––réprimand with initial stress does double duty for many speakers as both a verb and a noun––the important and unalterable fact is that no matter how many syllables the word has, if there is a contrast at all, the stress in the verbal form will be NON-INITIAL, i.e. be on one or more syllables closer to the end than in that of the nominal form. Moreover, and just as importantly, THE REVERSE IS NEVER TRUE: there are no English verb/noun pairs which contrast by having an initial stress in the verbal form and a non-initial in the nominal form.
Where a non-initial stress is retained in the nominal form, it tends to acquire stylistic value, such that this (unproductive) variant is necessarily associated with formal or neutral diction by comparison with an extant (productive) variant that is associated with informal or colloquial style. This is the case with items like defáult vs. défault: the first form is typical of a neutral or high style, whereas the second occurs in informal or colloquial contexts, the latter typically including the vernacular of sports.
Moreover, once the colloquial variant gains general ascendancy, it may become terminologized, by which is meant a specialized occurrence as a constant feature of a certain sector of the vocabulary. Thus, no person familiar with the jargon of sports would ever confuse offénse ‘a violation or infraction of a moral or social code, etc.’ with óffense ‘the means or tactics used in attempting to score, etc.’; or defénse ‘the act of defending against attack, danger, or injury’ with défense ‘means or tactics used in trying to stop the opposition from scoring, etc.’ (Note in these particular cases that the verb differs from the noun by having a d in final position [offénd, defénd].)
The drift of the language is just as straightforwardly clear, viz. toward the regularization of initial stress for BOTH grammatical categories regardless of stylistic differentiation. This is the overall trend which accounts for the emergence not only of non-standard nominal variants like défault or óffense but the replacement of traditional non-initial stress in verbs like frequént by contemporary innovations with initial stress. This historical trajectory is evidently to be explained by what can be called the THE LAW OF THE SUPERSESSION OF THE MARKED BY THE UNMARKED, which dictates that, ceteris paribus, linguistic oppositions distributed contextually only by the markedness value of the terms tend to generalize the unmarked value regardless of context.