Training Speed In Tai Chi Chuan

Everybody has probably heard this joke:
"A guy goes into a bar-
-outside the bar, a Tai Chi master is defending himself from a drunk-
-the first guy has three drinks, then leaves the bar-
-outside the bar, the Tai Chi master is still s-s-slowly defending himself-
-(que snarky laughter)...
When people think of Tai Chi, they usually picture old people moving slowly and methodicly in a park. So what is it about this art that manifests it's nature in slow movement? How can something so slow be used to defend oneself if attacked?
For the purpose of this article, I will generally refer to the Yang style, which I practice, and is the most common style practiced world-wide. It is true that the Chen style (and perhaps others) have some explosive movements in their forms, and Chen appears to be the root of other styles. But let's look at the Yang form.
It is generally believed that moving slowly and carefully allows the practitioner to measure each movement precisely. This makes for smooth efficiant movement.
At a seminar several years ago, Stick-fighting expert Bruce Chu told us about an expert marksman he knew in the military. When asked about his shooting success, the marksman said: "Smooth is fast; slow is smooth; so slow is fast". In other words, his success was from slow methodical method, even in "rapid fire".
In Bruce Frantzis' book on "The Power of Internal Martial Arts", he describes a paradox in how slow movement manifests itself into incredibly fast and efficiant actions. He suggested there is almost a time-lapse phenomenon where an old master is not necessarily faster than a young attacker, but finds the gaps in the attacker's techniques and exploits them in a seemingly magical way.
Part of the illusion of Tai Chi as strictly a slow moving form is that most people never learn the CHUAN (fist) aspect of Tai Chi Chuan. While it used to be called "The Supreme Ultimate" of Chinese boxing, it is precieved in the west today as new-age hippie-dippie yoga. To a certain extent, that is true. Many Taiji students never play with push-hands or partner forms. Most can't figure out applications of the form because they have never tried, and are happy to just be doing some gentle movement that makes them feel good. Well, that's fine, but they are missing so much that they could explore to make every aspect of their skill better.
In an excellent article by Peter Lim Tian Tek titled "Taijiquan Training Speed", he reviews historical record of fast, compact and explosive fighting techniques in the Yang family forms. For instance, here is a quote refering to the form of Yang Chen-Fu's older brother Yang Shao-Hou:
"His taijiquan 'frame' style was originally similar to his brother's, but later it gradually changed to the style of high 'frame' with lively footwork and well-knit small movements, alternating quick with slow actions. He was swift and powerful in delivering his blows and, with eyes blazing like torches, a grim smile on his face and roaring and howling as he darted back and forth, he was held in awe by others" (Gu Liu Xin, his introduction to 'Yang Style Taijiquan' by Yang Zhen Duo, 1988, page 7)
-- So while learning the form, it is necessary to be slow and precise. But once the form is committed to memory and you have complete freedom of movement, we should have elements of fast, explosive action spontaneously come out in the form. Not a whole series of movements, but a piece here and a piece there. Moving Yin (slow) into Yang (fast), is perfectly in keeping with the philosophy of Tai Chi Chuan. Please check out the article linked above for further historical context.
And remember; "Smooth is fast; slow is smooth; slow is fast".