The original TIE Starfighter first entered Imperial service years ago. It proved to be one of the most effective symbols of the Emperor's power and "foreign policy". Despite its success, the design was aging and inadequate against the latest New Republic starfighters. As a result a replacement for the TIE Starfighter was produced. The Shadow Imperium's (and later Crimson Empire's) TIE Dagger, was similar in concept, but with many improvements.
First, the traditional circular cockpit window on all earlier TIE models was replaced. The new rectangular, bevelled window afforded the pilot an unobstructed 180 vertical degree view of space. The new single piece of transparisteel removed the necessity of structural braces across the window as found on older TIE's which obstructed the view.
The profile of the new TIE Starfighter was reduced. The clunky, massive solar panels on the original were replaced with smaller, more efficient units similar to what was found on the TIE Interceptor. The wings were also angled outwards to provide a larger field of fire for the four laser cannons.
Finally, perhaps the most innovative new design feature were the swiveling weapons. Each laser was mounted on a swiveling emplacement, and could rotate up to 30 degrees. The angled segments of the wings were also hinged allowing a "variable geometry" firing pattern. These two articulations in the laser system were tied in with the automatic targeting computer which automatically adjusted gun positions to track a target. The result was much higher laser accuracy and fewer wasted shots.
Like its predecessor, the new TIE Dagger lacked shields and hyperdrive. Shields and hyperdrive greatly increased the cost of the fighter and it was decided that they should be left off. This more simplistic design allowed for much faster production at a much lower cost, allowing the deployment of hundreds of the new TIE's in a very short period of time. In addition, the smaller profile of the fighter allowed more of these fighters to be packed into a hanger bay. With the new fighters, a Star Destroyer's standard complement could be increased from 72 to about 96 fighters.