Bazi - Day Stem's Strength? 八字 - 日干的强弱?

Attended a Bazi lesson in Melaka by Master Leyau this evening.  We learnt how to determine if the day stem of a bazi is strong or weak. 

There are three ways to look at it:

1. 得令 (de-ling) - If the person of the bazi is born in the right season, his bazi is considered strong. For example, a person with day stem 壬 (ren), 壬 is yang water, if he or she is born in the winter season, this day stem is considered strong because of 得令.

2. 得地 (de-di) - If the person is not born in the appropriate season in relation to the day stem, the day stem can still be considered strong if its year, month, day or hour branch has supporting season or elements. For example, a person with day stem 甲 (jia), 甲 is yang wood, if his year, month, day or hour branch has 寅, 卯, 亥, the day stem is still considered strong because of 得地.

3. 得势 (de-shi) - If the person has other heavenly stems (year, month or hour stems) which is of the same element as the day stem, OR the other seven heavenly stems and earthly branches has elements that produces the day stem, the day stem is considered strong because of 得势.