This paper discusses connections between a national culture and the culture inspired by software development methods (SDMs). Specifically, based on our research on cultural issues related to software development teams, we propose a model that can help predict whether a specific SDM fits a specific national culture. This model first defines the terms 'tightness of an SDM' and 'tightness of a national culture'. With respect to an SDM, this term articulates the idea that the tighter an SDM is, the more ordered the software development process and environment it inspires will be; with respect to a national culture, the term 'tightness' reflects the degree to which a culture accepts and adopts ordered, planned and procedural work habits. The model then goes on to outline means that can help in the mapping of a given SDM, as well as a given national culture, along the following five dimensions: Project plan, procedures and standards, responsibility, time estimation, and individual need satisfaction. Finally, based on these mappings, the fitness of a given SDM and a national culture is examined. It is proposed that this fitness can serve as a tool for predicting the degree to which a given SDM will be accepted by a specific national culture in general, and by a specific team that is part of that culture, in particular. The model is illustrated using the Israeli hi-tech industry as an example of a national culture and Extreme Programming (XP) as an example of an SDM.