Which political forces and actors have been involved in the instability of the party system resulting from the presidential elections in Argentina? From a descriptive analysis in which are examined in the elections developed in the period 1983-2015, the new and relevant political forces as well as the candidates for president and vice-president belonging to the latter, it will be indicated that those candidatures have been integrated by political actors with previous experience in public service. As a result of this, it will be argued that the new and relevant political forces responded to processes of competitive adaptation headed by political actors already inserted within the system and not by outsiders to stand for election. In this sense, it will be demonstrated that all the new and relevant political forces in the argentine presidential elections have been electoral alliances, but many of them have involved in their candidatures, political actors that had recently split from their former allies. This paper analyzes the degree of relationship between splits and alliances in the presidential elections in Argentina between 1983 and 2015. With this objective, four general questions are presented: a) what percentage of the relevant alliances (in electoral terms) in the entire presidential elections involved splitting processes?; b) what percentage of splits resulted in alliances between the relevant forces?; c) what were the political forces with which the actors were identified at the moment of splitting?; d) what factors urged the actors to carry out a split? On the one hand, it will be shown that the majority of the alliances counted in their presidential formula with splits and that the totality of the latter opted for the former to compete in the elections. On the other hand, it will be indicated that most of the divisions came from political forces in power and that the reasons which induced them were related to: differences in the process of determining candidacies, the division with the top leadership and the discrepancies in terms of the policy of alliances.Este trabajo analiza el grado de relación entre las escisiones y las alianzas en las elecciones presidenciales argentinas entre 1983 y 2015. Con este objetivo, se presentan cuatro preguntas generales: a) ¿qué porcentaje de las alianzas relevantes (en términos electorales) en la totalidad de las elecciones presidenciales involucraron procesos de escisión?; b) ¿qué porcentaje de escisiones derivaron en alianzas entre las fuerzas relevantes?; c) ¿cuáles eran las fuerzas políticas con las que los actores se encontraban identificados al momento de escindirse?; d) ¿qué factores impulsaron a los actores a llevar adelante una escisión? Por un lado, se demostrará que la mayoría de las alianzas contó en su fórmula presidencial con escisiones y que la totalidad de estas últimas optó por las primeras para competir en las elecciones. Por otro, se indicará que la mayoría de las escisiones provinieron de fuerzas políticas en el poder y que las razones que las indujeron se relacionaron con: diferencias en el proceso de determinación de candidaturas, la división con la cúpula dirigencial y las discrepancias en torno a la política de alianzas.