Base strength trend on periodic table

[orangeman25]

So as you move from right to left on a periodic table, base strength should increase because electro negativity decreases.

However, I'm confused on the trend when you move up or down a column. On one hand, moving up should increase base strength because the conjugate acid gets weaker. On the other hand, electro negativity increases going up so base strength should decrease. Which one is it?

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[brood910]

For familes, you consider size, not EN.
Especially for haloacids. Larger size = more acidic = less basic.
It's because larger conj bases can stabilize themselves better by spreading negative charges more widely.
More stable = less basic.

However, for oxyacids, size does not matter. Even if halides are included, you consider # of oxygens + electronegativity. So, the ones with F will be more acidic than the ones with I.