Slim, this is from the DiMeola website and is what I based my assertion on. I am not vouching for its accuracy but it does sound reasonable.
*snip*
To get a cigar to start spicy, turn mellow and finish rich, as do DiMeolas, fully fermented tobacco needs to be blended and rolled properly. For spiciness, the tips of the filler leaves, the most flavorful part, should be placed in the “tuck” (the end that you light, which novices in the business often refer to as the “foot”). The tips of the leaves, grouped in the tuck will produce a burst of flavor. Then, when rolled properly, filled out not too tight, not too light, the cigar will proceed in an even burn and begin to pick up mellowness and richness, until at the finish it is at its best. Why?
In a word, Nicotine, cigar tobacco’s primary, natural flavoring agent (there are no artificial flavors used in truly fine, premium cigars). While fermentation eliminates up to 25% of the nicotine in cigar leaf, what remains is grouped primarily in the tips of the leaves, and also along the edges descending toward the base. So, if the filler is rolled into the cigar correctly, a rush of spice is generated on lighting and shortly thereafter.
As a properly constructed, fermented cigar is smoked, nicotine distills out of the smoke stream behind the heat cone and builds up there. As the cigar becomes shorter, the stream passes through more and more nicotine, thus becomes more flavorful, until the finish, when it can be the tastiest of all.
This explains why a cigar of, say, 46 ring, 7 inches long, will taste different when it reaches 5 inches than a 46 ring cigar that starts at 5 inches.
*end snip*